Let’s Talk About the Phillies’ Playoff Odds (!) by Dave Cameron May 19, 2016 It’s May 19th, and the Phillies are in first second place in the National League East. Yes, the Phillies. The team that generated a 1,000 “tanking is ruining the sport” articles this winter has, six weeks into the season, the third-best record in the National League. As Jeff Sullivan noted this morning, their remarkably excellent bullpen has been one of the primary drivers of the early success, with David Hernandez and Hector Neris surprisingly emerging as dominant forces in the middle innings, and Jeanmar Gomez driving another nail into the coffin of the necessity of a “proven closer”. And yet, despite being in second place at this point, if you look at our current playoff odds, you wouldn’t actually know that the Phillies are off to a great start. See that flat line across the bottom? That’s the Phillies. Their 24-17 start hasn’t moved the needle, at all, on our forecasts expectations for their chances of reaching the postseason. Okay, that’s not exactly true; they’ve gone from a 0.1% chance of winning one of the two Wild Card spots in our preseason forecast all the way up to a 0.3% chance of getting to the play-in game now. But their odds of hanging on to the NL East? Still close enough zero to round down when displaying one decimal point. This is, to some, puzzling. A question in my chat yesterday brought up the point that our system is far more bearish on the Phillies hot start leading to postseason success than others; Baseball Prospectus gives them a 2.3% chance of winning the division and a 7.6% chance of getting a Wild Card spot, for 10% overall odds of reaching the playoffs. FiveThirtyEight is even more bullish than that, putting them at 4% to win the NL East and 13% to reach the postseason. So why is our system so stubborn relative to others attempting to look into the same crystal ball in order to see what the final standings will look like in October? Well, it’s worth noting that there are dramatic methodological differences between the way that we (and BP) do our forecasts and the way FiveThirtyEight is doing theirs. Our forecasts are essentially an amalgamation of individual player projections, summed up at the team level; BP does this same thing too, using their PECOTA projections where we use a mix of ZIPS of Steamer. FiveThirtyEight, on the other hand, is using Elo Ratings, which adjust up or down based on whether you win or lose a game, and how much of an upset that win (or loss) was relative to their pre-game expectations. While they used individual player projections to come up with their preseason Elo ratings, their in-season adjustments are based on responding to a team’s win-loss record. Our system doesn’t care at all about a team’s actual record at any point in the season; it only looks at the individual player performances to try and ascertain whether there have been significant changes in expected playing time or production level to adjust the team’s expected record up or down. So far, ZIPS and Steamer look at what the Phillies players are doing and think “yeah, that’s basically what we expected.” Our preseason expected win% for the Phillies was .395; 41 games into the season, our rest-of-season expected win% for the Phillies is .396. And because they were starting from such a low baseline of expected wins, even their extra banked wins through the first six weeks don’t really change how often they make the postseason in our simulations; the strong start has taken them from 64 to 72 projected wins, but nobody’s making the playoffs at 72 wins, or anything close to it. And that’s part of the reason why FiveThirtyEight’s playoff odds are so much more optimistic than ours, even beyond the different methodologies for adjusting to in-season performance. In their preseason forecast, they had the Phillies as a 68 win team, an expected winning percentage of .420, which produced a 2% chance to win the division and a 5% chance of reaching the the postseason overall. Now, with their hot start included, FiveThirtyEight’s forecast has the Phillies finishing at 77-85, which gets them close enough to have variance carry them into the mid-80s or even low-90s over enough trials. But to get from 24-17 to 77-85, that still means that FiveThirtyEight is only forecasting the Phillies to go 53-68 the rest of the way, which translates out to a .438 winning percentage. That’s up a little bit from the .420 preseason expectation, but not a ton; it’s the difference between seeing them as a 68-win team or a 71-win team over a full season. Their system is more responsive to in-season results than ours is, but there’s still a good amount of “don’t overreact, it’s early” baked into their forecasts. Interestingly, it’s BP’s system that has had the most dramatic change of heart about the Phillies expected performance from this point forward. Prior to the season, they had the Phillies being as lousy as we did, putting them at 65-97 in their initial forecasts, a .401 winning percentage. If you go to their playoff odds page today, though, the Phillies are projected for a whopping .450 win%, and are now expected to finish the season at 79-83; that puts them at 55-66 over the rest of the season, two wins better than what FiveThirtyEight projects, and eight wins better than what we expect. Despite having the middle value in terms of playoff odds, BP’s system is the biggest believer in the Phillies going forward. Well, sort of. It’s maybe more accurate to say that BP’s forecasts suggests a belief in a very small spread of talent in MLB right now; the top team (the Cubs) have a forecast .572 win%, while the worst team (the Braves) checks in at .441. We have the Cubs at .594 and the Braves at .403, so our top-to-bottom win% spread is 191 points, while BP’s is just 131 points. The Phillies are still seen by PECOTA as one of the worst teams in the league, but since the gap between teams is seen as quite small in their system, even the worst teams still have a fighting chance at the postseason. Of course, I should mention that there’s actually a fourth playoff odds calculation out there; we have a “season-to-date” stats mode that eschews the projections entirely, and only evaluates a team based on their 2016 numbers. This isn’t a great system, since throwing out what we know about players and teams heading into the season means we’re discarding useful information, but it’s a useful thing to look at and see what we’d expect the odds to be if we really didn’t know anything about anyone beyond how they’d played this year. And in that model, the Phillies are expected to finish at 77-85, with a 5% chance of winning the division and a 10% chance of grabbing a Wild Card spot; even with their 24-17 record, their lousy offense and poor run differential makes the system think this is still not a good team. Also fun; in season-to-date mode, the Cubs finish with 113 wins! So, with a bunch of different systems producing wildly different results, what’s the “right” number for the Phillies chances of reaching the postseason, considering they sit in second place on May 19th? I think there’s a decent argument to be made that our system isn’t responsive enough to in-season changes; combining two projections systems together adds regression-to-the-mean by balancing out outlier forecasts, and so it’s pretty difficult for a team to move the needle in a big way in our forecasts. But, to be honest, I also have a hard time buying the high numbers put out there by BP and FiveThirtyEight; we’re talking about a roster currently running a 73 wRC+, after all. Their pitching has been outstanding, but pitching is a fickle beast, and their current BaseRuns record even with that excellent pitching is just .410. I don’t see any real reason to think that the Phillies can keep winning one-run games at the level they have been, and with a lousy offense and young starting pitchers that are likely to have some innings limits put on them, I think expecting something closer to our 72 win forecast sounds more likely than the 77-79 win forecasts spit out by other teams. But certainly, there are enough unknowns in forecasting that no one should be defending their projections as gospel, and perhaps the fact that BP and FiveThirtyEight are producing significantly higher playoff odds than we are should serve as evidence that our numbers are too low. After all, we certainly weren’t expecting the Phillies to be in second place in mid-May, so perhaps our forecasts could be improved by adding in some adjustment for team performance above and beyond individual player projections. With multiple systems and different methodologies out there for public review, we’ll be able to look back at the end of the season and see which one best projected what a surprising first-place team did over the final three-fourths of the season.