from Amazon
Friday, May 02, 2008
What can happen when you take a team’s stats too seriously, while ignoring player projections
You end up with ridiculous conclusions. BP says that these teams have the highest chances of making the playoffs:
80.3: Arizona
68.9: Oakland
53.9: Chicago (AL)
52.1: Tampa Bay
How can TB be on the list and not Boston? Boston is the better team with the better record! What about CLE, an excellent team in a division with teams that have terrible records, other than CWS, who are a terrible team? Why is OAK on the list, but not ANA, when they have the same record, and ANA is the better team?
Those numbers, as well as the rest of the numbers in BP’s playoffs odds, are ridiculous because they are using some kind of silly system to compute each team’s expected wp for the rest of the season, which involves, I think (it is impossible to tell, when you have 136 different labels, stats, explanations, etc.), putting a great deal of weight on a team’s current season “something,” be it w/l record, pythag. record, underlying EQ hitting and pitching, or whatever, and then doing some kind of regression toward .500, rather than just doing what they do at the beginning of the season, which is using each player’s projection, both performance rates, and playing time, which is THE correct way to do it.
I say what they are doing is silly and wrong not because I know and understand exactly what they are doing (I don’t), but only because if you look at the results, you can easily see that they make zero sense.
As you can see from these, and their other “playoff odds,” numbers, doing whatever they are doing, is spitting out obviously ridiculous numbers.
Check these out:
The Angels, with an 18-12 record, and obviously a good team, based on everyone’s pre-season projections, including BP’s own, are somehow now a .486 team going forward, if I am reading their charts correctly (which is no easy task)! How is that possible? I assume that they must have some kind of bad underlying offense and defensive numbers so far this season. I don’t really know.
The WS, a bad team, somehow are now a .537 team now going forward, better than the Phillies, Mets, Braves, Boston, Yankees, and Tigers.
I don’t think I need to go on. Does anyone at BP actually look at these numbers to see if they make any sense? Because they don’t.
I am looking at the “post-season odds report” and then the link to their “adjusted standings report” and I can’t make much sense of it, so I will admit that the “pct3” column may not be their expected wp going forward, although I think it is, but either way, the final expected w/l for each team, as well as their expected odds of making the playoffs, are ridiculous.