It’s all over! The votes are in, they have been counted, and I can announce that the winner of The Big Internet Math-Off is:

**Nira Chamberlain!**

Massive congratulations to Nira, you may now refer to yourself as The World’s Most Interesting Mathematician*.

* of the 16 people I asked to take part, who were available in July, and wanted to play.

Nira’s pitch on applied mathematics won 56% of the vote in the final, with 1207 votes against 960 for Matt Parker’s pitch on naive fraction addition.

I don’t *get* applied maths – it never appealed strongly to me – so I really appreciated Nira sharing his obvious enjoyment of it. And apparently so did the voters!

I asked both finalists to sum up their Big Math-Off journeys. First, here’s runner-up Matt Parker:

It was an honour taking part in the Big Internet Math-Off. And by coming second in a 16-participant knock-out competition I now know that I’m somewhere in the range of 2nd to 9th best overall.

And now, here’s the World’s Most Interesting Mathematician, Nira Chamberlain:

My Big Math-Off Journey was definitely a month long roller coaster ride. I made a conscious decision to showcase three applied mathematical pitches as well as the Black Heroes of mathematics. So why did I do this and not go for an interesting recreational mathematical pitch? It is because when I present at a school, the children just love applied mathematics and at the end of the day I am an applied mathematician.

First round, James Tanton – Infinite Cakes, was jaw dropping amazing. I am still shaking my head over it.

Second round, Alison Kiddle – Ebert’s hat problem was a serious battle as I opted to go for The Black Heroes of Mathematics, showing little to no mathematics in my pitch. However, of all of my pitches this is the one which has received the most positive feedback.

Semi-Final, Zoe Griffiths – The ‘phantom’ parabola. Now Zoe pulled the best move of the entire tournament when she posted a picture of a cute kitten on Twitter! From being 40 votes behind me, she raced 40 votes ahead in a short space of time. When the scores became tight again, I posted a picture of cute puppies! All fair in maths and war.

The Grand Final, Matt Parker – Naively adding fractions. Within the first 6 hours, Matt ran into a 50 then 60, 70, 80, 90, 100+ lead. I have never been so far behind. However, Christian made this a 48 hour competition not a nine hours one. The feedback from social media was that the Black Panther’s mathematical model was very cool.

Though I won this tournament flying the applied mathematics flag, the real winner is all of mathematics. The variety and quality of pitches were amazing. My favourite pitch was the Collatz sequence by Edmund Harriss. Watching his animation reminded me why I am a mathematician – because

mathematics is undisputedly the best subject in the whole wide world!

Hurrah!

So, that’s that out of the way. Now, I’d like to spend the rest of this post summing up the competition in a few ways.

### We saw loads of fun maths

The best thing about the competition for me was seeing 30 pitches, delivered by people who were really excited about the fun maths they’d chosen to share.

There was a huge range of pitches…

What I’d like to do is list the 5 pitches that got the most votes, and then 5 of my favourites of the other pitches.

#### The most popular pitches

**Matt Parker with pathological voting, 1244 votes** – Matt claims to have been trying to get knocked out of the competition. He shouldn’t have picked such an interesting topic! This was one half of the epic Parker/Harriss semi-final.

**Edmund Harriss with curvature, 1226 votes** – The other half of that semi-final. Curvature is a really nice idea, that I’ve never fully understood. I *nearly* got it when BBC’s *In Our Time* recently did an episode on Gauss, but Edmund’s description was just brilliant. His Curvahedra are a brilliant tactile way of exploring curvature, too.

**Nira Chamberlain with mathematical modelling, 1191 votes** – Makes sense that the pitch that won the final should appear in this list, right? Nira put together everything he loves about mathematical modelling in this video, and the crowd went wild for it.

**Matt Parker with naive fraction addition, 953 votes** – And here’s the other half of the final. After all his shenanigans in previous rounds, I really appreciated Matt picking a nice, straightforward bit of maths that he had enjoyed thinking about.

**Edmund Harriss with Penrose tiles, 541 votes** – It’s widely agreed that the connoiseur’s favourite in this match was Colin’s card trick, but that’s only because the connoisseur has already seen Penrose tiles. Can you remember the first time you heard about them? It’s incredible that they exist at all! Edmund loves them, and that’s what this competition’s all about.

#### My favourites

Basically, they’re all my favourites, but I’m limiting myself to 5 that particularly stuck in my mind.

If I’d been voting, I would’ve picked roughly zero of the winners of each match, which I suppose confirms my status as *unberable maths hipster*. Aren’t you glad I let the public decide, rather than my obscure tastes?

A few of these pitches are now in my mental back-pocket as the go-to explanation when I want to tell someone about a cool bit of maths, and some were just plain new to me. I really enjoyed seeing new things: as a turbonerd who literally maintains a catalogue of his obscure maths knowledge, I was hoping the 16 competitors would show me at least a couple of things I hadn’t seen before, and they did not disappoint!

**Colin Wright with a pack of cards** – I’ve seen this before, maybe even from Colin, but it’s now firmly stuck in my head as “something you can show someone, convince them of, and leave them to think about a proof for a week or two”. It’s sort of like that question about counting nested figure 8s, which I “know” but can’t recite a proof of.

**Tony Mann with the secrets of the universe in a random number** – Brilliant presentation of an idea that’s incredibly hard to pin down rigorously. Tony deftly avoided that, and explained the gist in a memorable way. The only pitch that made me laugh out loud.

**Zoe Griffiths with the aeroplane seating problem** – I didn’t have high hopes for this when Zoe said she was going to pitch it, but her video is just about the best presentation of the problem that I can imagine. I particularly love the animation of Cinderella sliding into her seat.

**Alison Kiddle with Haga’s theorem** – I think this one was new to me. There’s a world of origami theorems I don’t know, and I’m glad Alison told me about this one. Theorems to do with paper are always good to break out when in the vicinity of non-mathematicians.

**James Propp with the disappearing knot** – I still don’t know if Jim was trying to slip something not-entirely-true past us. I need to get some rope and have a good long think about this pitch.

### The admin

I decided to run a competition involving:

- 16 competitors around the world with full-time jobs and varying degrees of experience presenting maths on the web
- online polls, which could be brigaded at any moment
- a recklessly tight schedule
- typeset mathematics

all while

- bringing up a 9-month-old baby
- working my own full-time job

Katie and Paul’s wedding was an admin tour de force. There was branded bunting. There was a programme. There was a large-print programme. The toilets were stocked with every kind of toiletry that a human could conceivably need. I think she might be a superhero whose superpower is preventing entropy.

Katie Steckles is very good at admin. Katie Steckles is so good at admin that we have basically staged an intervention and banned her from doing admin on the site when she could be doing paid work.

I’m **not** good at admin. In fact, I don’t want to harp on about it, but I do have a learning disorder that makes me particularly bad at admin. The night before last I made myself a delicious packed lunch for work, then yesterday I got two hours into my workday before realising I had in fact left it at home. That was one of my better days. I’m not good at admin.

With all that in mind, I can’t believe I managed to pull it off. I had the idea for the competition in early May, talked the format through with Peter and Katie, spent a few weeks emailing people asking them to take part, then spent June sending a series of progressively more desperate emails to the competitors asking them to send me first of all their ideas for pitches, and then their first pitch.

So: pat on the back to me, and thank you to all the competitors for doing what I asked, sticking with the competition, and not going AWOL hours before their match was due to start. We got close to that a couple of times, but it all came together in the end.

### The competitors

I’ve been calling this “Christian alienates all of his pals but one month”, because asking your friends to compete against each other for approval on the one subject they all have in common is probably not the kind of thing Debrett’s approves of.

Somehow, all 16 competitors are still speaking to me. And some of them are now speaking to each other, having been introduced to each other in the competition. Success!

There’s been a lot of talk amongst the competitors about where rank in the competition, having been knocked out at different stages. I’m going to avoid overthinking for once, and list them in the order they were knocked out.

**James Tanton** – James is a superlative maths enthusiast, and I think he rather undersold his first pitch, as fun as it was. If we’d had a loser’s bracket (and a clone of me to run it) I’m sure his next pitch would’ve been incredible. If I’d seeded the competitors, he definitely wouldn’t have ended up against Nira in round 1!

**Samuel Hansen** – Sam couldn’t really deal with being knocked out in round 1, so just kept putting out pitches on their podcast that they would’ve used in the later rounds. I really respect that kind of never-say-die attitude.

**Peter Rowlett** – I’ll be honest, I asked Peter to take part when I had 15 competitors and not enough days to find someone else. The potential conflict of interest made me uneasy, so I was quite glad he knocked out immediately. I was happy to see the parabola line drawing thing, and Peter’s very relatable pitch on how it affected his mathematical development.

**Colin Wright** – Never mind my flawed methodology, Colin is one of the world’s most interesting mathematicians. While I thought coming up with 4 topics to pitch might be a bit of a stretch for some of the people I asked to take part, I think Colin could happily come up with new bits of fun maths indefinitely.

**Tiago** **Hirth** – Of all the competitors, Tiago is definitely the most mysterious to me. I knew I wanted him to take part, but I struggled to come up with a description of what he does, or even where in the world he spends most of his time. I’m glad he obliged me, though I still don’t understand the rope trick he pitched. And in true Tiago fashion, the pitches he would’ve made in later stages will remain forever a mystery. I couldn’t even work out from the titles he gave what they would’ve been about.

**Matthew Scroggs** – If you like my whimsical maths thinkings, you’ll love Scroggs. Even though he didn’t make it out of round 1, you got two pieces of fun maths from him, thanks to Matt Parker’s shenanigans. My heart grew two sizes when I saw that Scroggs had made a Ceefax page with the competition schedule and results!

**James Propp** – One round wasn’t enough to capture just how interesting Jim is. I’m going to add this competition to the time I interviewed him for an hour for a podcast that I couldn’t use in the list of Times Jim has Humoured Me To Absolutely No Personal Benefit. I’ll try to atone, however slightly, by pointing you to his blog and asking you to read all of it.

**Tony Mann** – Tony’s dry wit and innocuous appearance hide a wicked mind. Tony doesn’t have a huge web presence, so I’m greatly looking forward to seeing him again in person at the big MathsJam in November. I hope he puts together more videos like his round 1 pitch!

**Alison Kiddle** – Where Nira went for expansive areas of maths, Alison likes to focus on little bits that you can think about for a while and happily file away for later enjoyment, like a mug of mathematical cocoa. Greatly appreciated.

**Paul Taylor** – The other of my Aperiodipal ringers, enlisted when I ran out of time to chase up other potential competitors, I was quite glad he saved me a potential conflict of interest by getting knocked out. You shouldn’t be glad though, because Paul’s completely unexpected approaches to otherwise standard topics are a joy.

**Evelyn Lamb** – In my mind, there was a dichotomy between the ‘puzzlers’ and the ‘explainers’ in this competition, but Evelyn ploughs her own furrow: she wanted to write about maths that was new to *her*. I admire that greatly!

**Jo Morgan** – Appropriately for a teacher, Jo got her homework in way ahead of time, and exactly fit the brief I set. I wasn’t sure if hexaflexagons were a bit too well-known to do well, but there are always more people who haven’t heard the Good News, and the enthusiastic pitch didn’t hurt. I’m going to keep the Klein bottle limerick from round 2 in my wallet, or make a sticker or something.

**Zoe Griffiths** – While I’ve met Zoe a couple of times, I hadn’t seen her talk maths properly before. She’s good! I thought for a while that we might have a Think Maths face-off in the final, against Matt Parker. It wasn’t to be, but we’ll always have that aeroplane puzzle video.

**Edmund Harriss** – I really wanted a mathematical artist in the competition, and Edmund was the right man for the job. If you’ve ever sat down and tried to make some “math art” (I have), you’ll quickly realise it’s really hard to come up with something new and good-looking. Edmund achieves that repeatedly. Furthermore, the descriptions in his pitches were brilliant too. Another casualty of the absolutely brutal format!

**Matt Parker** – When I was trying to enlist competitors, a common refrain was, “won’t Matt Parker just walk it?” There was always going to be a popularity element to the competition, and Matt does have a devoted following, but his matches were a lot closer than many (not me) expected. He says he was trying to knobble himself to avoid embarrassment, but he couldn’t resist pitching some genuinely interesting bits of maths. Mad respect for keeping to his word and taking part while filming a DVD with Festival of the Spoken Nerd and flying halfway across the planet in the middle of the final.

**Nira Chamberlain** – One of the two competitors I haven’t met in person yet, and before the competition started I’d only briefly interacted with him while organising Black Mathematician Month last year. I knew he’d bring a different perspective, and boy did he!

You’ve only had a glimpse of what each of the competitors enjoy about maths. They’re all unendingly keen to share fun maths things any day, anywhere, so I highly recommend you follow them on social media, read their blogs, and try to be in the same place as them whenever you can.

Have I thanked them enough for taking part? Thanks again for taking part, you lot!

### Post-match interviews

I sent the competitors a few questions to sum up their Big Math-Off experiences.

#### Have you learnt anything new during the Math-Off?

**Tiago Hirth: **

For SURE! A lot of awesome pitches.

**James Propp:**

I learned a number of mathematical things, but my favorite was Zoe Griffiths’ explanation of the airplane seating problem. I’d seen other explanations before, but hers was the clearest I’ve ever seen.

I also learned something about the people who voted: either many of things I regard as old chestnuts are new to them, or they don’t care about novelty as much as I do.

I appreciated getting a chance to see what topics people tended to like. Over the next year you can expect to see one or two of the winning topics treated (with my own spin, of course) in Mathematical Enchantments.

**Zoe Griffiths:**

Yes! Mathematically: I learnt something with pretty much every post. Probably Paul’s Pythagorus one gave me the greatest ‘Aha’ moment.

About myself: Make it competitive and give me a deadline and I’ll do it.

**Tony Mann:**

Yes, lots of nice maths, including new angles on things I already knew, and a little from observation about running internet competitions. Also, as someone else said, a reminder of how the canon of well-known maths is always changing, and that what is well-known at one time may not be well-known a few years later. And finally, that it is important to enjoy the maths and not take the votes in internet polls too seriously!

**Edmund Harriss:**

Yes! Even when the mathematics was familiar I really enjoyed seeing how it was presented. My favourite new piece was Colin Wright’s card trick, perhaps in part because I was up against it, so engaged that bit more. It is delightful when it works out.

**Alison Kiddle:**

Yes! Lots of stuff, both mathematical, and about maths communication!

**Matthew Scroggs:**

Yes, Colin’s card trick was new to me. I still need to find a spare evening to sit down and work out how it works.

**Samuel Hansen:**

Nope, already knew all of this…

Ok, ok that is a lie. I have learned a ton of stuff, most interestingly that it is possible to generate real excitement around a math competition (well in the UK at least)

**Peter Rowlett:**

Of course, I’ve learned lots of new things during the Math-Off. Some of them from the Math-Off entries themselves.

**Evelyn Lamb:**

I learned a few things during the math-off. When I wasn’t voting for ties, I tended to vote for things that were new to me, and almost every match had something new to me. (Not easy because at this point most “fun math(s)” books are all old hat for me.) I was a little surprised that the entries had so many puzzles (though I liked a lot of those pitches). I’m really not a puzzle-motivated mathematician. Sometimes one will grab me, but I’m more interested in other things in math.

**James Tanton:**

Lots of really cool math and new twists of familiar math. I’ve also learnt (well, this is knowledge that has been reinforced) that there is a spectacular community of math folk doing mighty good uplifting work for the world, bringing the joy of math so beautifully to the world.

#### Are there any pitches you particularly want to highlight?

**Tiago Hirth: **

Jim’s on ropes … but I’m highly partial.

**James Propp:**

I liked the way Evelyn Lamb tried to describe a recent mathematical breakthrough. In some ways it’s harder than doing what the rest of us did (describing older work that’s been better assimilated).

**Zoe Griffiths:**

I really enjoyed Paul Taylor’s two entries – both clearly presented, something people could think about themselves and really unique. I also enjoyed Alison Kiddle’s Hat Problem – maths we could think about/do at home, and included comment about its wider use, that was easy to understand.

In general I preferred ones that showed me maths I could do/think about myself, rather than ones that highlighted a piece/area of maths that would have required further research to gain a proper understanding of.

**Tony Mann:**

I particularly liked, as a pitch, Zoe on the airplane seating problem – the problem was (unless my memory deceives me, which is quite possible) new to me and it was beautifully presented.

Also the maths presented by Jim, Colin and Tiago particularly appealed to me. There were lots of other excellent pitches but I seem (without setting out to) to have picked out the ones that were new to me.

**Edmund Harriss:**

One of the best aspects of the competition was the diversity of the pitches. I have enjoyed pointing people to the competition as a whole as there is something for many audiences, from ideas and activites that are easy to try oneself to beautiful images, to discussions of advanced mathematical topics (even with Evelyn Lamb’s sphere packings new mathematics). I particularly appreciated Nira Chamberlain’s introduction of a cultural and political element, especially with his “Black Heroes of mathematics”.

**Alison Kiddle:**

I’ve already told Zoe that her explanation of the airplane seating problem made me engage with a problem that has always frustrated me, and actually got me to understand something involving probability, so that deserves a special mention.

**Matthew Scroggs:**

Alison K’s folding construction and Paul T’s proof of Pythagoras were both very neat, and made me go “oooh”. Colin W’s aforementioned card trick surprised me. Zoe G’s plane puzzle explanation was very elegant: I remember doing this puzzle a few years ago and getting to the answer and a much messier way.Although I’ve enjoyed all the pitches. It’s been a great month for maths!

**Peter Rowlett:**

I just went through my wall chart and worked out I voted for the winner in precisely half the matches, excluding the final. So, whadda I know?

Tony’s video made me chuckle. I found Edmund and Matt’s semi-final the hardest to decide, not that I was particularly convinced about any of my votes (except for Alison in round 1) as they were all good pitches.

**Evelyn Lamb:**

I really liked Paul’s Pythagorean proof. I amuse myself by making pretend conspiracy theory-style rants about how the Pythagorean theorem is a definition, not a theorem, and I might try working that in. I thought Alison’s hat problem pitch was adorable because I’m very capable of being flattered. ;) I thought Jim’s not-a-rope-trick entry was a perfect example of an entry in the style of Jim, and I do love his writing. Tiago’s video about Borromean rings was so charming, and I was sorry to be against him in the first round. I loved both entries in the Matt-Matthew competition.

**James Tanton:**

I too was struck by Zoe’s presentation of the plane puzzle. But I really did love all the pieces I read/watched and I look forward, very much, to going back and looking at them all when I have time.

#### What would you have done differently?

**Tiago Hirth: **

Perhaps a group phase in the beginning :)

**James Propp:**

I would’ve made snazzier choices (now that I’ve gotten a feeling for what the voters like). Maybe I would have made a video.

**Zoe Griffiths:**

Made 15 more friends by the end of my semi-final. That’s a joke. I’d have improved my explanation of Bedford’s Law!

**Tony Mann:**

Listened to my friend who was trying to tell me how to register multiple votes (that’s a joke – and in any case Colin has told me that it wouldn’t have worked.)

Thought more about my initial ideas before submitting them.

In terms of the competition as a whole, I think it worked perfectly – the diversity of approaches, styles and topics was great and I hope the next one will preserve that.

**Edmund Harriss:**

As I was able to do three pitches I tried to adapt as I went on.

**Alison Kiddle:**

To be honest, I don’t think I would change my pitches – I was knocked out by a very worthy entry by Nira, and I was leading at various stages in our competition, so I am happy with my performance. I certainly wouldn’t try to emulate what other people did successfully – part of the beauty of the competition for me is that the pitches were varied in

topic, presentation, style, personality… if we’d all produced the same things, it would have been bland.

**Matthew Scroggs:**

Put MENACE up as my first round entry, so we could all marvel at a MENACE v MENACE match.

**Samuel Hansen:**

I would have remembered to ask my family to vote which I think would have been enough to power me past Paul in our very close first round match.

**Peter Rowlett:**

It went perfectly, from my point of view. I offered to take part if and only if you needed me to make the numbers work for a single-elimination tournament. Then I was on holiday during the first part of the competition, and really didn’t want to take time away from playing with my son to write a second round post. So I’m pleased to have given Alison a run for her money and received some nice comments about my entry, without winning our round!

If I had wanted a different outcome, I might have campaigned more vociferously! The competitions with big turn out seemed to make good use of Twitter maths hashtags, for example. Which is, of course, good for everyone because more people learn about cool maths stuff.

**Evelyn Lamb:**

I wouldn’t have been on a road trip during one of my matches. :) I wish I could have been a little more active promoting the match I had with Zoe. I was out of town that weekend and at a busy event, so I was too tired and busy to check in much on it. I would have liked to get more people looking at the pitches and voting in general, whether or not it changed the outcome at all. Also I would have proofread that entry better. (The hazard of finishing it up in a hurry while getting ready to leave on that road trip!)

**James Tanton:**

I was struggling trying to figure out the level of the pitch and predicting the audience level. Also, I do wish I put forward a polished piece, not a rushed something. (Well, playing with messy cake was just fun and how polished can that be?) The quality of the work of all the participants was stunning! Thank you all!

#### Finally, what do you think CLP’s Extremely Fair system for deciding ties is?

**Tiago Hirth: **

You choose your favorite, which I would consider close enough to random for anyone that doesn’t know you, given that Dunbar’s number holds and you don’t become a well studied person …

**James Propp:**

I think you use some far-out bits of pi as a surrogate for randomness.

**Zoe Griffiths:**

Is it simulating the Aeroplane Seating Problem? If person n gets their own seat then competitor 1 wins, if person n doesn’t get their own seat then competition 2 wins? I’ve heard that’s 50:50.

**Tony Mann:**

No idea.

**Edmund Harriss:**

For each round pre-roll “higher” or “lower” the entry with the appropriate word length wins. Or just toss a coin. Alternatively a count back. The pitch that was last in the lead wins.

**Alison Kiddle:**

Some sort of Paul-the-octopus like test involving his daughter?

**Matthew Scroggs:**

Entry containing the word with the highest Scrabble score wins.

**Samuel Hansen:**

Whoever has written the most posts for the Aperiodical.

**Peter Rowlett:**

Some function guessing thing a la Katie’s competition.

**Evelyn Lamb:**

I think your Extremely Fair tie system is a coin flip.

**James Tanton:**

The person with the lowest power of 2 which begins with their date of birth wins.

#### Anything else you’d like to say?

**James Propp:**

Suggestion: maybe the eventual winner should, in addition to receiving the glory of being crowned World’s Most Interesting Mathematician, inherit the burden of having to run the next Big Internet Math-Off the following year!

**Edmund Harriss:**

A huge thank you to Christian for setting this up, especially in the context of having a small child in the house. Even with everyone really just wanting the mathematics to take the lead, a competition sets up a bunch of emotions, hinted at in “Christian alienates all but one of his friends month”. I know you dealt graciously with mine and my respect and friendship for you has only grown.

**Evelyn Lamb:**

*I talked a bit about this on the Big Math-Off episode of Relatively Prime – CLP*

If something like this runs again, I think it’s important to try for a more diverse entrant lineup. I know that can be tough, and I would be happy to help make some suggestions if asked. Having only one person of color and four non-men was less than ideal, in my opinion. (And my apologies if I have made incorrect assumptions in my count here.) I know from a response you made to a comment that the demographics of the entrants don’t reflect the demographics of the people you asked, but I think if something like this runs again, it would be hard for me to be enthusiastic about it if the demographics don’t change. I say this with a lot of appreciation for what you put together and the great competitors who participated!

One final thankyou to all the competitors!

If I’ve learnt one thing, it’s that I really need a deadline to make me get things done. I was going to add a load of analysis to this post, and enlist the magic graph fairy to draw some graphs of the voting patterns, but I’ll save that for later.

Maybe we’ll play again next year?

I just wanted to say thank you to Christian for all his efforts in running this and to all those who have taken part for sharing so many great things with us. It’s been a brilliant alternative or adjunct to the usual summer of sporting competitions, and I do hope it will run again. I look forward to catching up with some of you at the MathsJam conference in November. My favourites were Nira’s Presentation on black mathematicians, Zoe’s brilliantly clear explanation of the aeroplane problem, Colin’s cards and Matt choosing something simple and not trying to gerrynander the results in the final like he did (very amusingly) in the preceding rounds.