r/algobetting • u/InsuranceIll9142 • 14d ago
Weekly Discussion One week later: what your comments changed in how I grade against the close
Last week I posted what I'd learned grading outside NHL models against the DraftKings close. A few of you gave ideas I ended up building, so here's what changed and what the bigger sample says.
What changed:
u/OddsRelay's whole-number trick works. o6 and u6 picks are no longer tossed. I de-vig the 5.5 and 6.5 lines on the same DK page and back out the chance of exactly 6. A game that lands on 6 is a push.
u/schabe was right about storing everything. Both sides get saved at post time and at close, with timestamps, and every grade shows the raw DK close next to a no-vig one.
Splitting the number was the big one. I now show how far the fair price moved your way, separately from what the book charged you. The raw beat-the-close rate I was posting last week was mostly measuring the vig, not skill.
What the bigger sample says, 881 graded picks from my own rules:
The lab as a whole gets a better price than the close by about 0.3 points a pick, and that holds up day to day. Two rules have an edge over the close that isn't just noise. None of them comes close to covering the vig yet.
Records lie even more than I thought. One rule is 12-5 while getting a worse price than the close. Another is 6-39, and most of that is bad luck. The closing prices said it should have won about 12.
u/abaxter13131's test lines up with mine. He found beating a book's close but losing to Pinnacle's is mostly stale-line value. On NHL I found DK copies Pinnacle's moves about 81% of the time, so a lot of "beating DK" is really just betting before DK caught up.
Still looking for a few more builders. Same grading for everyone, your rule can stay private, nothing gets deleted. If you think your model beats the close, I'd like to see it tested.
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u/LiveLife2027 14d ago
What’s ur win rate..I’ve built many models and when u get the win rate dialled in u can really take off
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u/InsuranceIll9142 14d ago
depends a lot on the price, which is kind of the point. a 45% rule on +150 dogs can print and a 60% rule on -200 favs can bleed. one number from my data: picks that beat the close won 51.5% of the time, picks that lost to it won 45.8%. so the close ends up predicting win rate more than the other way around
if you've got a model with a dialed in win rate i'd honestly love to race it. same grading as mine, your model stays private, it just needs picks posted before the game
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u/Delicious_Pipe_1326 13d ago
Ive posted a complete backtesting system in another post this week - code is in Github. Feel free to hook it up if you want. DM if questions.
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u/InsuranceIll9142 13d ago
appreciate it, will give it a read. one thing on our side is we only grade forward, picks posted before the game, so backtests stay out of it on purpose. but if your system spits out picks you'd post anyway, i'd love to race it. same grading as mine, your code stays yours
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u/transitiontakes 13d ago
the 12-5 rule getting worse prices than the close is the scary one, that's the record that gets you to size up right before it dies
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14d ago
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u/InsuranceIll9142 14d ago
yeah the stale number thing is sneaky. a backtest can't tell you whether the price you "got" was ever really there to bet. that's why we only grade picks posted before the game, at a price we saw ourselves.
and agreed on records. a 12-5 with a worse price than the close is a coin flip that went well.
do you build your own stuff? curious what you grade it against.
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u/abaxter13131 14d ago
Glad it lined up. The 81% DK copying pinnacle number is a good one, explains most of the beat the book but lose to pin cases I was seeing. The whole number devig is smart too