Showing posts with label Pythagorean Records. Show all posts
Showing posts with label Pythagorean Records. Show all posts

Thursday, June 21, 2007

By the powers of Ron Santo

During one of our irregular, meandering internet conversations today, I offered the following prediction to Pepe: The Cubs would very likely be in serious contention for the NL Central this season up until the end of the season, and I don't believe it's out of the question that they could actually win the damn thing. Cue incredulous scorn from my counterpart, who mentioned three reasons why he doesn't believe this is the case:

1) The Cubs are currently 8.5 games out of first place in the Central;
2) The Cubs sucked in 2006;
3) The players on the Cubs suck, at least in contrast to current front-runner Milwaukee.

The first two are obvious truths, and the third is a subjective claim. I'll get to No. 3 in a minute.

Currently, the Cubs' record sits at 32-39, which is good for third place in the putrid NL Central. There is no question that, for a team that spent a total of $300 million during the offseason, this is a disappointment (and further evidence that spending and success in baseball do not share a direct correlation). If the Brewers continued to play at this pace, the Cubs would have to sport a .652 winning percentage for the rest of the season, which is greater than the Red Sox's current pace (.648). That is unlikely, to say the least. So, if one were to formulate his or her opinion of the Cubs' playoff chances based purely on W-L records, it would appear safe to stick a fork in the North Siders and crown the asses of the Milwaukee Brewers.

But that would assume that W-L records are useful as predictive tools, and there's no reason to think that's the case, particularly in this situation. First, the Brewers and the Cubs have played 71 and 70 games, respectively, which is roughly 43 percent of the season. That's far from a large enough portion of the season to draw reliable conclusions about what will happen for the remaining 67 percent of the season (particularly considering that remaining part of the season is likely to include a large number of roster changes, via trades, injuries or call-ups). If Prince Fielder breaks his jaw on an overbaked hoagie tomorrow, and misses a couple of weeks while being fed intravenously, one cannot expect the Brewers to keep playing this well. Conversely, if the Cubs finally give touted prospect Felix Pie enough at-bats for him to start playing to his potential, the Cubs could begin playing better both offensively and defensively (more Pie = less Jacque Jones). So, there are a lot of variables that will determine these two teams' fates for the rest of the season.

But there's also the issue of what a current W-L record is based on. While a W-L record is the only measure that matters to a team when it's all said and done, that doesn't mean it's an accurate indication of how well (or poorly) a team has played to date, or how well/poorly one can expect that team to continue playing from here on in.

So, what is? A couple of things. Most notably, there's the concept of a team's Pythagorean Record, a concept created by Bill James that has since been modified to allow for more factors, including run-scoring environments (See here for a rather dense explanation). A Pythagorean-based calculation results in First-Order Wins. Then there are two other measures, referred to as Second- and Third-Order Wins. These are based on Equivalent Runs, a measure that attempts to place value of an offensive performance of players based on playing time and position. Second-order wins are a stepping stone to Third, which used Adjusted Equivalent Runs, a measure that takes into account to opposition and environment (for example, the value of a HR off Jake Peavy in PETCO park is greater than the value of a HR off Woody Williams in whatever the fuck they call Enron these days). I'll be honest and admit that the how of arriving at these numbers is a little mind-boggling — it bears mentioning that the people who came up with these formulae are not only way smarter than me, but also highly educated in the field of statistics and mathematics — but that doesn't mean the what is any less valid.

Here is BP's adjusted standings page, which list the first-, second- and third-order wins of all the teams in the major leagues. It takes a second to process everything, and I suggest looking at the legend to clarify exactly what it is you're looking at.

Now, I know what you're saying: "So the fuck what? Just because some nerds have come up with a measure doesn't mean that it means anything. A team's W-L record is what's important, because that's what determines post-season eligibility." And that's obviously the case. But what we're attempting to do here is figure out, with some measure of accuracy, what teams are going to do for the next 67 percent of the season. I know that some people still scoff at the notion, but luck has played a role in the success and failure of teams so far this season. The Brewers, for instance, started off the season like gangbusters, and built a massive lead early on. Obviously, the team couldn't support that rate for the entire season, and regressed. Conversely, the Cardinals were absolutely horrible to start out the season, but eventually began playing better because they weren't really that bad. However, those small periods of time still have a massive effect on the W-L records we see now, because those unsustainable streaks have yet to be adequately buttressed with periods of normalcy, or even equally-unsustainable winning/losing streaks.

Based on what the BP chart tells us, the Cubs have played baseball at a level that is more likely to result in a 37- or 38-win record than a 32-win one. And — surprise, surprise — the Brewers have played at virtually exactly the same level. The BP charts indicate that the Cubs and the Brewers should be in a tie for first place in the win column, with the Brewers roughly one loss back.

I think the results that show on the BP chart are indicative of the usefulness of the measures; it's fairly accurate in nailing what the actual standings are, in most cases, and that accuracy rate will likely increase as the season goes on and the effect of random variation is reduced. I can't find the chart for 2006, but when I find one, I'll post it; it was quite on-point.

Luck isn't the entire story for teams that play below or above their Pythagorean records. Beyond possible inequities in strength of schedule thus far, the Cubs exemplify the kind of team that is highly susceptible to this kind of difference, mainly because of a poor record in close games. That usually is an indicator of a bad bullpen and a shaky defense, which fits with the Cubs. Furthermore, teams with low OBPs tend to be more slump-prone, as the success of an offense becomes more dependent on power and surges in hitting. That applies to the Cubs as well.

However ...

Teams that have a variation of more than a game or two between the actual W-L record and the Pythagorean records are outliers; it just doesn't happen all that often, because runs scored vs. runs allowed are easily the best single indicator of a team's quality. With that being the case, it is highly likely that there will be a correction over the course of the season for the Cubs, as well as the Brewers (to a lesser degree, since they're only playing roughly 2 games over their Pythagorean). It's likely that the Cubs will need to have a hot streak or two where they play above their heads, but that's not abnormal at all, almost to the point where it's to be expected.

At this point, the always-entertaining BP Playoff Odds Report (based on Monte Carlo simulations) shows the Cubs as having a 20 percent chance of winning the NL Central. I would suggest that the chances of the Cubs being "contenders" — a designation that Pepe set at being within two games back or less with a week or so left in a season, which is sensible — are much higher than that. The one thing I will back off on is that I'm not sure those chances are even-money or better; I can't begin to do the math needed to arrive at that kind of conclusion with any reliability. But I'm going to e-mail Davenport and see if he can shed any light on making that kind of conclusion.