Staturdays

Kyle Bennison

  • Pebble Beach Weather Leads to Favorable Odds

    Pebble Beach Weather Leads to Favorable Odds

    I just recently started following the PGA Tour, and even more recently started dabbling in betting on golf.

    Thankfully, there’s a site called datagolf.com—probably one of the greatest sports statistics and betting sites I’ve come across—which makes it very accessible to get started. They offer live finishing odds for every player in every tournament. For paid subscribers, they even offer betting tools and expected values for various bets using live odds from popular sportsbooks. This makes it really easy to evaluate bets in realtime. (The PGA Tour site, on the other hand, is one of the worst and most poorly-organized sites for stat nerds I’ve ever used.)

    The bet I was following on Saturday was the leader Wyndham Clark’s odds of winning. He had a two-stroke lead on the field, which by the end of the round was down to one stroke to second and two-strokes to third.

    My philosophy so far has been to put more trust in the players who have been there before as opposed to the newcomers. Whether this is valid or not is to be determined. And Clark, just this past season, had won his first two pro tournaments. Second place Ludvig Åberg had four wins, but just one on the PGA tour, and third place Matthieu Pavon had just one win as well. Further bolstering my confidence was the fact the Clark was playing great golf, posting a 60 in the third round. Perhaps I was falling into the hot-hand fallacy, if that exists in golf.

    At the end of the third round, datagolf had Clark’s odds around 29% to win. DraftKings was offering him to win at +200 (33% implied probability). This initally looked like a negative expected value (EV) bet.

    Now, my impression of his play that day, his previous experience, and who he was up against bolstered my internal odds to about 33%. But there was one element that was not factored into either of these odds yet: the elements.

    The weather forecast for Sunday was dire, with heavy storms throughout the day not expected to let up until the late afternoon. There was a chance they would postpone until Monday, but there was also the chance that the tournament would be suspended entirely. It seemed almost certain that they wouldn’t play on Sunday, but whether or not they would cancel I had no way to know. However, I knew it was at least a possibility, meaning I should bump my internal odds up higher still, turning this into a positive EV bet.

    If there was a 33% chance of Clark winning if they played, and a 100% chance of him winning if they cancelled, and a 25% chance that they cancelled, then his win probability should really have been around 50%! This turns into a high EV bet. It appeared that DraftKings, and possibly other sports books, didn’t account for weather and early cancellations in their odds models.

    A probability tree of the possible outcomes for Clark if they played or if they cancelled the final round.

    Even if you disagree with my upping the initial odds from 29%, as long as you agree with at least a four percent chance of cancellation given the weather forecast, that puts positive EV on the +200 odds.

    At 33% implied odds and 50% actual odds on the current leader, DraftKings was essentially offering people free money.

    It’ll be interesting to keep an eye on weather-affected tournaments in the future to see if they’ve learned anything from this situation.

  • Unhappy in Happy Valley

    Unhappy in Happy Valley

    Fans and reporters were not pleased after PSU’s loss to Michigan.

    After Penn State fell to Michigan 24-15 last Saturday, a reporter questioned James Franklin on his two-point conversion attempt in a now-viral video.

    The situation was this: Penn State just scored a touchdown and was down 9, with 1:59 remaining in the game. They opted to go for it, lined up in what we can all agree was a questionable formation, and the attempt failed.

    The counter-argument to the go-for-two decision boiled down to this:

    “If you kick the extra point, you’re down 8 and your team is still in it. Down 9 with 1:59 left, you’re done.”

    So there are a few issues with this argument:

    1. The assumption that the game is over down 9 with 1:59 left is wrong. There’s about a 1% chance that you can win (based on NFL data) in that situation. If PSU held Michigan to a three-and-out on the next drive, they could have gotten the ball back with about a minute left.
    2. If you’re down 8 (and you score again), you still need to go for two. So unless you think your team will magically be better at 2-point conversions next time, there’s no difference. (Penn State is 0-3 on the year, two of them in that game.)
    3. Whether you know you’ve lost the game with 1:59 on the clock or 0:00s on the clock makes no difference.

    Okay, so what does the math say?

    It turns out, there may be no difference, which is kind of what I was getting at up above. It doesn’t matter. Fans very passionately want to feel like they’re in it to the last moment. Coaches prefer to know what their options are ahead of time. Do I need an onside kick? Because if so I’ll do it now rather than later.

    I used Ben Baldwin’s 4th-down-calculator and the 2022 Lions-Packers to simulate this game since the Packers (Michigan) were 4.5-point favorites over the (Detroit, not Nittany) Lions (Penn State).

    On average, whether you make or miss either attempt, you end up with about a 2% win probability. Not great either way. But in the end, it looks like the decision was a toss-up. So the strong anger and one-sided debate are a bit surprising. But I’ll chalk it up to a frustrated fan base.

    What we don’t need to argue about is Franklin’s decision to go for two in the second quarter, down 14-9. Here, there was so much time left that going for two actually hurt their win probability.

    Now, this is contrary to what I just said earlier about knowing what you need ahead of time, so I think this outcome speaks to the cost of leaving free points off the board early.

    On the methodology: If I were more precise, I would pick my teams based on two-point conversion rates, PAT percentages, and two-point conversion defense, but there’s just not enough data to know that when PSU has only attempted three on the year and Michigan has only defended two (4th and short or 4th and goal can sometimes be a proxy for 2PA).

  • Should Pato O’Ward Have 2-Stopped at Mid-Ohio?

    Should Pato O’Ward Have 2-Stopped at Mid-Ohio?

    After Pato O’Ward’s poor qualifying effort which had him starting 25th at Mid-Ohio, the broadcasters in the NBC booth stressed that he had to “do something different”.

    And sure enough, the McLaren driver’s pit wall opted for a 3-stopper instead of the favored and eventual race-winning 2-stop strategy.

    Despite these setbacks, O’Ward still finished with the 3rd fastest total time in the field, covering 80 laps just 14 seconds slower than race winner Alex Palou despite finishing 28.5s behind on the track.

    Of course, qualifying better could have eaten into that chunk of time a bit, but could one-less pitstop and the 30 seconds saved have made up for his poor qualifying and seen O’Ward actually come from 25th to win?

    To analyze this, we need to consider two things:

    1. How much time would O’Ward have saved by pitting one less time? (This is the easy question to answer because it’s just the pit delta).
    2. How much time did O’Ward gain from having fresh tires on his extra stint, or how much time would he have lost being on older tires for longer?

    The net of these two things ends up being the delta between a 2-stopper and a 3-stopper.

    The second question is harder to answer because we don’t know how his tires would have held up, what traffic he would have hit, and all the other unknowns that may have occurred had he 2-stopped.

    The best we can do is see how the drivers around him were affected and extrapolate out to O’Ward’s race.

    Pit Delta

    The pit delta for O’Ward specifically can be found by looking at his pit-in and pit-out laps, and then comparing that to his normal non-pit green flag laps.

    O'Ward Pit Stop Delta Time lost over average green flag lap (seconds). Pit Stop 1: 33.307 seconds Pit Stop 2: 28.792 seconds Pit Stop 3: 26.775 seconds

    The Pit Delta also changes as the race progresses, and particularly the 3rd stop delta was quicker for O’Ward because he needed less fuel, so we will use that delta instead of the overall average. His 3rd stop was 2s quicker than his 2nd stop and 6.5s quicker than his first.

    So his 3rd stop added 26.775 seconds to his race time vs. staying out and doing average-paced laps.

    Green Flag Pace

    Green Flag Lap Times by Strategy (seconds) 2-Stops: Average Lap Time: 70.603. Std. Dev. Lap Time: 1.206. 3-Stops: Average Lap Time: 70.354. Std. Dev. Lap Time: 0.961.

    O’Ward’s green flag non-pit lap times on average were 69.8 seconds. The drivers on the 2-stop strategy were averaging 70.6 seconds per lap, but we care more about the fastest of the 2-stoppers, Alex Palou and Scott Dixon.

    They were both averaging 69.95. So on a typical green-flag non-pit lap, of which there were 69 for O’Ward, he was only 0.15s faster than Palou. So that equates to about 10.4s gained over those green flag laps on pace alone.

    So he gained 10.4s by choosing a 3-stop over a 2-stop, but lost 26.8s in pit-road time, for a net loss of 16.2s with a 3-stop strategy. This tells us that O’Ward likely should have stuck with a 2-stop strategy.

    Compared to the field, the 3-stopper made sense as he was almost a full second quicker per lap than the average 2-stopper, meaning he made up 55s on the field to counteract his 27s stop. But the fastest 2-stoppers were able to keep a similar pace to him even on longer stints.

    Navigating Traffic

    What likely hurt O’Ward was all the extra passes he had to make thanks to that extra stop. O’Ward started in 25th, so he had a bigger gap to make up and 24 cars to get by. He was already 6.6s behind Palou at the end of the first full green flag lap.

    O’Ward had to overtake 43 cars for position in the race, 14 more than the next-closest driver. Palou and Dixon were among the lowest in the field, with just 10 and 13 overtakes, respectively. This number doesn’t cover the backmarkers, although all drivers would have to deal with them eventually.

    You can see this take effect in the data too. While O’Ward had the fastest green-flag pace of anyone, he also had one of the highest standard deviations in lap time, meaning he was not able to be consistent. The difference may seem slight, but it is enough to make an impact on your race, and this accounts for the significant amount of extra time he spent behind and navigating around his competitors.

    You can see from the green flag lap charts that O’Ward was much more inconsistent than Palou over the course of the race, with spikes and dips in pace.

    Tire Difference

    The last thing we’ll look at is the tire dropoff, which undoubtedly helped O’Ward to pump out laps almost a whole second faster than the field average throughout the race.

    The reds and primary tires were similar until lap 15 of a stint, when the reds fell off sharply by about 0.5 seconds. At 25 laps, both tires were 1 second slower than at their best.

    As you can see, there’s about a 1-second dropoff from lap 10 to lap 20 on the reds, and about a half-second on the primaries. The reds seemed to come back a bit near the end of the stint, but that could be drivers just pushing them to the max before pitting.

    Luckily for O’Ward, he was on the primary most of the race which appears to be preferable if you want to go more than 15 laps. However, as the race went on and the traffic built up, his pace got slower and slower and his lap times more unpredictable.

    When To Do An Extra Stop

    This is a question that I want to do more research on, but my initial thoughts after doing this analysis are:

    1. You have to take track position and traffic into account. If you are going to have to re-pass more than 2 or 3 cars by pitting, it’s going to cost you a significant chunk of time. 3-stopping probably makes more sense for leaders with a big gap who want to protect against tire dropoff than it does for mid-pack trying to make a big move.
    2. Track length and cars on track matter. A short 70-second lap like Mid-Ohio with 27 cars on course appears to be the wrong place to do an extra stop. There’s too high a chance of coming out in traffic and dealing with backmarkers late in the race.
    3. Tire dropoff matters. If tire dropoff isn’t significant, then you don’t have as much to gain on fresh tires vs. worn tires. Similarly, if the difference between reds and blacks isn’t significant, then doing shorter stints on softer tires won’t be as big of an advantage.
    4. Cautions change everything. If more cautions had fallen later in the race, the analysis changes completely. Time lost on pit lane is mostly erased. Restarts provide easy overtaking opportunities.