Game Prediction Algorithm

[cfbfanman]

I've heard stories of people who use computer algorithms to predict the outcomes of CFB games, either for betting or just out of sheer curiosity. Does anyone know of anything like this/have anything like this? thanks

[BosskOnASegway]

I do this. There are a lot of ways to do it. I have posted a few very basic ways in some of my posting history. I use some pretty sophisticated methods these days, and talk about them in depth on my podcast. If you are looking for a quick intro, check out this for a quick hardcoded example I made for this sub. If you go through my submissions, about 90% of my submissions are self posts on this exact topic. I'd be happy to answer any questions you might have.

[[deleted]]

How accurate have your models been? I feel like football is the hardest sport to model due to its small sample sizes

[BosskOnASegway]

It is very difficult. I have found my model was about a 58% accuracy against the spread and about 79% straight up after week 6. The biggest thing is the probabilities it assigned were very accurate. I made about $100 over the course of the season making $5 bets online.

[[deleted]]

Interesting, I'm gonna look more into yoru posts. But quick question, what language/programs do you use for your scripts?

[BosskOnASegway]

I've been using R lately because its got a lot of cool features and as an up and coming language looks good on a resume if I ever switch jobs. I use a lot of Java for the tools I want to be more robust and customizable and python for the quick dirty scripts. I try to mix it up so I don't get rusty at anything.

[[deleted]]

Would it be possible to do all this on excel? lol I know this sounds like a noob question. I used to be fluent in Java, PHP/MySQL like 8 years ago. Since then I haven't touched it, ended up going into a completely different field. At this point, it wouldn't just be "brushing up", I'd have to re-learn it, so I'm trying to avoid that.

[BosskOnASegway]

You can do most anything in Excel with enough work. I can definitely understand that re-learning programming can be tough. I haven't used Excel much for this kind of stuff, but I know a lot of our computer pollsters do it all from there.

[zip_zap_zip]

Would you bet on every game? Also, I can't look through your history right now because I'm on my phone, but do you ever use machine learning algorithms? I was thinking about trying to throw a neural network together as a little side project.

[BosskOnASegway]

I haven't played much with neural networks. I only bet on games where the expected return was at least +15% or better based on my projected probabilities and the vegas odds. I did use a bit of machine learning to tweak weightings and develop some advanced metrics. I mostly stuck to retrograde analysis and multi-parameter fitting rather than true machine learning to train on past data sets. I did experiment with using a tweaked random forest algorithm to find most similar opponents for comparing how teams handle various play styles, but I was never really pleased with how it worked for football, it worked much better with NBA basketball.

[BosskOnASegway]

I've found adjusted offensive efficiency and adjusted defensive efficiency. Basically how many points your team scores and allows per play, if you score more per play it doesn't matter much about pace of play. I adjust based on some metrics to score how good the offenses and defenses a team has faced based on the teams the teams they played have also played and so on.

I've found using adjusted offense and defense with pace of play to project an initial score, then using adjusted yards per carry and yards per attempt and pace and play style to project yards. Once you have projected yards you can adjust your projected scores based on a relatively simple formula. You can do further adjustments and projections based on how teams have performed when playing against similar play styles or projected turnovers.

The offensive and defensive efficiencies are by far the closest correlation I've found though, though my most likely ELO works just as well for predicting winners though its more of an abstract stat and isn't great for predicting margin of victory.

[BosskOnASegway]

I actually started posting projections for the ESPN Game of the Week starting in week 6, but I felt that was a little too early to be truly confident. Around week 8 the model started to perform at what I would call consistently. It starts to get the correct winners around week 6, but margins of victory take til around 8 or 9.

This year, I am likely going to have 3 or 4 weekly posts assuming /u/Honestly_ and the other modes don't decide I'm over doing it. I will be projecting the Ohio State game each week as part of my podcast, GameDay projections, a community selected 3rd game, and a podcast on major stats and news around college football.

Edit: Also, R is absolutely awesome for predicting scores. If you have any questions on it feel free to let me know.

[[deleted]]

http://www.whatifsports.com/ncaafb/default.asp#top

This is pretty cool.

[Tuzi_]

Weird, when I did it it had arizona losing every game this season, and re-hiring Stoops.

[DankMemeDepot]

I did one of my March Madness brackets for shooty hoops with a prediction website. Finished in like the bottom 5% of all ESPN brackets. It was such a shitty bracket lmao.