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Subject: Re: Two-point conversions - fun analytics? Author: Northbounder [ Next Thread | Previous Thread | Next Message | Previous Message ] Date Posted: 09:55:19 09/22/24 Sun In reply to: Bengal 's message, "Lehigh 35 Princeton 20" on 22:19:51 09/21/24 Sat Indulge me in some Sunday morning math. Let's (a) take extra points for granted, (b) assume two-point conversations are successful half the time, and (c) assume you have a fifty-fifty shot of winning in overtime. You're down fourteen in the fourth quarter. Having a chance means scoring twice and holding your opponent where it is. You do so. Behind Door #1 are two extra points. You make both and send it to overtime. Probability of winning, door #1: 50%. Behind Door #2 is a two-point attempt after the first touchdown. Things get trickier here, but bear with me. - If you make it, you win the game by one point, since you'll kick an extra point after the second score. This happens half the time. - What happens the other half of the time? Well, you're down eight, but you're still not out of it. In order to win, you have to make a second two-point conversion, and then you have to win in overtime. That's doable. Within this narrower ("already missed the first try") scenario, that happens one-quarter of the time. Overall, it happens one-eighth, or 12.5%, of the time: one quarter of one half. Add those together, and you get as the total probability of winning, door #2: 62.5%. This is the thought process. Watch nationally and you'll find two-point attempts in precisely this scenario a growing trend. [ Next Thread | Previous Thread | Next Message | Previous Message ]

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[> [> Subject: Re: Two-point conversions - fun analytics? Author: observer [ Edit | View ] Date Posted: 11:31:55 09/22/24 Sun Analytics measured in gross sample sizes don't account for true probabilities across many various levels of a sport. Nor does it account for field conditions, weather, practice time/repetitions, fitness, skill set variability, etc. It doesn't make sense to sacrifice bunt at the MLB level. At the NCAA level, the ability of infielders to react and execute is less competent than minor league ball. At high school, even more so, and in little league... Same goes for FG/XP conversions. NFL kickers are now nearly automatic. FBS kickers less so. FCS kickers, etc. etc. The high school coach who never punted never made his philosophy work at a higher level. Many sports data analytics-minded folks have forgotten another STEM principle that affects sports results: entropy. There's a reason why state governments have permitted sports gambling by phone, and companies are competing hand over fist to get licensed by the state lottery orgs. The vigorish is too good, and the "true probabilities" are unknown to armchair quarterbacks. [ Post a Reply to This Message ]

[> [> [> Subject: Re: Two-point conversions - fun analytics? Author: Northbounder [ Edit | View ] Date Posted: 20:49:01 09/22/24 Sun I agree fully that skill determines strategy. What a high school coach sees in a graphic during a broadcast on a Sunday should not dictate his own thinking. What may lead to success on Friday nights is only intriguing to Presbyterian College administrators until it stops working on Saturdays in Clinton, South Carolina. I disagree with your last graf. Your conclusion seems to be that the retail gambler fails because non-measurable factors influence outcomes beyond his ability to account for them. My impression is that the retail gambler fails because he has markedly less data relating to measurable factors than the institutional gambler. With that data, purchased at and thus valued at vast sums, the institution can then develop much more accurate estimates of the "true probabilities" – and in turn to set terms of wagering favorable to itself. I don't mean to suggest data solves or determine all — far from it. But were there no value, you wouldn't see the investment — not just from books but from teams and programs themselves. [ Post a Reply to This Message ]

[> [> Subject: Numbers, Numbers, Numbers. I Love Numbers. Author: An Observer [ Edit | View ] Date Posted: 15:08:35 09/22/24 Sun Northbounder, thank you very much for your post. I love this kind of analysis, though your particular example still makes me uncomfortable. As context, I've said for many years that, when a team has particularly effective short-yardage personnel, it needs to go for two points much more often. I've posted here in the past about two specific examples: Yale with Varga and Princeton with Lovett. With those two exceptional weapons, the probability of converting the two-point attempt is so high that it gives you an entirely new offensive weapon: turning the "extra point" into an "extra score." I've said many times that, if I were Yale or Princeton in this circumstance, I would go for two ANY TIME I scored a touchdown to go up by thirteen or more points. You're already up by two touchdowns; tacking on two more points forces your opponent to then start matching you two-pointer for two-pointer. Meanwhile, you've got Varga or Lovett and they don't. That wins for you, both in the short term and in the long run. But going for two when you've just scored to be DOWN fifteen? I don't know. I love your mathematical approach and, if that's what Surace was thinking, I can respect his analytic approach to the game. More than any other Ivy football coach, Surace plays to win, as opposed to not to lose, a common attitude among football coaches at all levels, including the NFL, where it is epidemic. That's why guys like Dan Campbell immediately get our attention. He and Surace are out there trying to WIN with every decision they make. Having said that, I think you need to consider a few other things. First, you'd better be damn sure that you're at least 50% to convert the two-pointer. Secondly, you've got to know your guys. Will they be discouraged if the try is unsuccessful? They've just scored a touchdown and losing momentum immediately afterward can be a kick in the shin. Northbounder, the logical extrapolation to your thinking is that teams should go for two almost any time that they score a touchdown. As I've pointed out above, that makes particular sense when a coach expects a high-scoring game and he's got Tyler Varga or John Lovett standing next to him. But in a game where three touchdowns might win it? I would love to hear Bob Surace or Dan Campbell walk me through their logic. The Lions of course were burned by their aggressiveness against the 49ers in last year's NFC championship game, and Princeton did not cover itself in glory yesterday. I want to hear the explanation after a BAD day, not a good one. Thank you for your take, Northbounder. [ Post a Reply to This Message ]

[> [> [> Subject: Re: Numbers, Numbers, Numbers. I Love Numbers. Author: Northbounder [ Edit | View ] Date Posted: 19:02:42 09/22/24 Sun As you've implied, the assumptions at the top of my earlier post are just those: assumptions. Got Varga? Two-point odds go above even. You're Vanderbilt and you're keeping it close with Missouri? Maybe your overtime odds are below even. I assume NFL teams have models to provide estimates of such probabilities and reference them frequently in-game. Whether coaches listen to them - a different story. The "logical extrapolation" you've mentioned is seen in what the Houston Rockets did with the three-pointer and what many teams in Major League Baseball have done with hitting approaches. The question of a kick vs. a two-point try provides much more mathematical gray area (we're not talking a half-point per-possession spread on threes vs. elbow jumpers compounded out over dozens of possessions). But if one generates a higher expected point total than the other, why not default to it? Maybe there is no good rebuttal to that. But I tend to agree with you. Ultimately, you don't want to miss the forest for the trees. The goal is not points per possession; the goal is to win the game. Hopefully the models are oriented towards that. (And even then, in the case of scoring to go down 8 late in the fourth quarter, the "correct" mathematical — barring exceptional deviations from default assumptions — is clear. But as the poster above you wrote, where's the accounting for momentum, for crowd energy, for player belief?) [ Post a Reply to This Message ]

[> [> [> [> Subject: Why Going For Two Points When Down 8 Works, Mathematically Author: An Observer [ Edit | View ] Date Posted: 14:32:11 09/23/24 Mon Northbounder, I called a couple of my friends who are mathematically inclined and discussed your post with them, guys who are in the numbers business. You have just ruined the last 24 hours for us because we have been wrestling with not just HOW your two-pointer strategy works, but *WHY*. A few minutes ago, I was standing at a urinal taking care of some non-numbers business when suddenly the light bulb finally turned on in my head. It seems that, mathematically, by going for two points down by eight in the fourth quarter, the scoring team manufactures out of thin air the extra 12.5% probability of winning you say results from that choice. How can that possibly be? How can 12.5% probability of winning simply materialize from choosing from nothing but 50% outcomes (making a two-pointer and winning in overtime? It's taken me a full day to figure it out. Let's call the two strategies KICK-KICK and TRY-TRY. The expected value of KICK-KICK is 2. Because the probability of converting a two-pointer is 50%, the expected value of TRY-TRY is also 2. So why is TRY-TRY the better strategy? Because part of the value of TRY-TRY comes from scoring 4 points with MAKE-MAKE. The expected value of 2 comes from 0.25% probability of each of these outcomes: FAIL-FAIL = 0 prob-adjusted value of this outcome = 0.0 FAIL-MAKE = 2 prob-adjusted value of this outcome = 0.5 MAKE-FAIL = 2 prob-adjusted value of this outcome = 0.5 MAKE-MAKE = 4 prob-adjusted value of this outcome = 1.0 Expected value of TRY-TRY = 8/4 = 2.0 But as discussed, if the team MAKES the first try, it will kick after the second touchdown. There will never be a MAKE-MAKE outcome. So the scoring team sacrifices the possibility of scoring 4 and improves the possibility that they will score 3. FAIL-FAIL = 0 prob-adjusted value of this outcome = 0.0 FAIL-MAKE = 2 prob-adjusted value of this outcome = 0.5 MAKE-KICK = 3 prob-adjusted value of this outcome = 1.5 Expected value of TRY-(TRY or KICK) = 2.0 But scoring 3 wins you the game outright, whereas scoring 2 only gives you a 50% probability of winning in overtime. The scoring team is shifting expected value from MAKE-MAKE and moving it to MAKE-KICK. That's where the extra probability of winning comes from. The scoring team is giving up the useless value of [the probability of winning by two] and increasinging [the probability of winning by one or in overtime]. It's taken me a full day to realize this and explain it to my math friends. Gotta use the urinal more often. Thank you, Northbounder, for a fascinating 24 hours in our lives. [ Post a Reply to This Message ]

[> [> [> [> [> Subject: Re: Why Going For Two Points When Down 8 Works, Mathematically Author: An Observer [ Edit | View ] Date Posted: 16:23:13 09/23/24 Mon Northbounder, now that I've reached my own conclusion as to not just HOW going for two works, but *WHY*, I'm consulting with my old friend Mr Google. According to one article which takes a very mathematical approach to this decision, during the 2015 and 2016 seasons, not a single NFL coach went for two points with his team down by eight in the fourth quarter. Not a single one. No idea how large the sample size was. Fascinatingly, if your team scores a touchdown to trail by ONE, this analysis says KICK and play for overtime if the opponent will have time for any meaningful drive (that is, not mere seconds). Turning your opponent loose down by one after your successful MAKE is apparently a bad outcome for you. When a desperate team is driving with nothing to lose and needing only a field goal to win, guess what? They succeed a lot. You're better off with the KICK and forcing your opponent fear making a mistake and missing out on overtime. [ Post a Reply to This Message ]

[> [> [> Subject: Tony Romo's Analysis Author: An Observer [ Edit | View ] Date Posted: 19:53:36 09/29/24 Sun Jim Nantz after today's Chiefs 17-10 comeback victory over the Chargers: "When Patrick Mahomes is down 10 points -- exactly 10 points, not 9, not 11 -- in his career, he is 12-0. What can we take away from that?" Tony Romo: "The first thing to take away is that you should go for two the first time you score a touchdown." [ Post a Reply to This Message ]

[> [> [> Subject: What's the proper play call when... Author: Go Green [ Edit | View ] Date Posted: 10:45:00 09/30/24 Mon ... you're up 40-23 with a minute to go in the game, and you're facing fourth and six on your opponent's twelve yard line? If you're Dan Swanstrom, the answer is throw a pass to the end zone to go up 47-23. :) [ Post a Reply to This Message ]

[> [> [> [> Subject: Re: What's the proper play call when... Author: An Observer [ Edit | View ] Date Posted: 11:20:41 09/30/24 Mon At least he didn't go for two. Seriously, I don't think Swanstrom is going to get a Christmas card from Tony Reno this year, but I'm okay with not taking a knee on fourth down. And if you're not going to take a knee, what's the difference between running the ball and throwing into the end zone? The "go for two" decision charts don't cover being up 23 with a minute to go, nor do they typically cover being down by 21 in the third quarter. Did you see the Georgia-Alabama game? Georgia trailed 30-3 at half time and then scored a touchdown about five minutes into the third quarter to cut it to 30-9. Kirby Smart immediately started going for two. I'd like to see what the analytics number crunchers have to say about that. Anyway, Georgia clawed their way all the way back to take the lead 34-33, when they continued their streak of going for two, this time for good reason, of course. Will be tough to top this game in 2024. [ Post a Reply to This Message ]

[> [> [> [> [> Subject: Re: What's the proper play call when... Author: Go Green [ Edit | View ] Date Posted: 13:10:51 09/30/24 Mon I didn't watch Yale-Cornell. I was just going through the write-ups and box scores. I have no idea if it was a chippy game and Cornell wanted to stick it to Yale. Not likely that Reno refused to lend Swanstrom equipment (like, oh say... a kicking tee). The game was in Ithaca so Cornell should have had everything handy. I didn't see Georgia-Alabama. But I did see Minnesota-Green Bay which pretty much went down in the same fashion. [ Post a Reply to This Message ]

[> [> [> [> [> [> Subject: Re: What's the proper play call when... Author: An Observer [ Edit | View ] Date Posted: 13:30:02 09/30/24 Mon I don't think that it's Tony Romo's job to make friends among other coaches in the Ivy League, but I can think of at least a couple other Ivy head coaches who would make it a point to score a touchdown with a minute left, already up 17. Interesting that Swanstrom went the same way with no prior history against Romo. As I said above, I don't have a problem with the call. There's a minute left. The other team is going to get the ball back and I expect Yale to play to the final whistle. Going for it on fourth down is acceptable in that circumstance. [ Post a Reply to This Message ]

[> [> [> [> [> Subject: Re: What's the proper play call when... Author: sparman [ Edit | View ] Date Posted: 17:39:53 09/30/24 Mon https://www.espn.com/college-football/playbyplay/_/gameId/401628374 GA tried and failed at 2PT following 3Q TD (@ 11:26). Had they kicked the EP, then when they scored their final TD in 4Q, they could have achieved their desired 3-point lead with the conventional EP. Now, if things had played out the same way, they still would have needed a TD to catch AL (because they would have trailed by 5 or maybe 6 points) after the final AL score, but such a TD would have given them the lead without having to convert another 2PT. And of course they still would have had to avoid the final INT. But I would rather be driving to score a go-ahead TD, than a mere tying TD that would have required OT or another 2PT to get the lead, which I will consider the next time I am coaching against AL. [ Post a Reply to This Message ]

[> [> [> [> [> [> Subject: What Should You Do When Down 30-3 at Halftime? Author: An Observer [ Edit | View ] Date Posted: 21:03:18 09/30/24 Mon Let's put Saturday night into context. Georgia coming all the way back from down 28-0 was the largest comeback *ever* in a game between two Top 5 teams. It was the largest comeback ever for the Georgia program (previous = 25). And the Bulldogs lost. Here's the way that I would look at the 30-3 halftime deficit if I were Kirby Smart. And like you, sparman, I don't expect to be offered the job but, like you I presume, if offered, I will accept. I'm down 27 points. That's a four-score deficit if I KICK after each of my four touchdowns. It's *still* a four-score deficit if I successfully convert all four TRIES, so there's no benefit to TRYing for two except for the scenario where I score three touchdowns, convert all three TRIES and kick a tying field goal while holding Alabama scoreless in the second half. What if I realistically assume that Alabama will score at least one more touchdown in the second half? In that scenario, my starting halftime deficit is 34 points. That's a five-score deficit if I KICK after every score. It's still a five-score deficit if I successfully convert all five of my two-point TRIES. Again, there is no benefit if I expect to catch up solely with touchdowns. There's only a benefit if I convert three or four TRIES after my four touchdowns and then kick a tying or winning field goal. Taking all of the above together, I would not have started going for two right after my first touchdown in the third quarter. Are there any antecedents in Ivy League football where a team came back from down 28? [ Post a Reply to This Message ]

[> [> [> [> [> [> [> Subject: 21 is Dartmouth's biggest comeback Author: Go Green [ Edit | View ] Date Posted: 08:37:42 10/01/24 Tue https://dartmouthsports.com/news/2017/10/7/211671841.aspx I'm sure most people remember this game more as the impetus for the Ivy adopting instant replay the following year. When Yale thinks they've gotten screwed, then changes happen. :) [ Post a Reply to This Message ]

[> [> [> [> Subject: Seahawks Go For 2 When Down 8 Author: An Observer [ Edit | View ] Date Posted: 22:25:52 09/30/24 Mon Seattle just scored a touchdown to pull within 8 against the Lions. The Seahawks went for two. Northbounder's once shockingly novel approach is going mainstream. [ Post a Reply to This Message ]