Thursday, January 07, 2010

Why Allowing Less Runs is Better Than Scoring More

In an interesting post to Blue and Orange, Chris Wilcox discusses the Jason Bay signing and the reaction by many Mets fans that adding a hitter did not solve "our problems." He argues:

Anyway, the point of this is not to defend the Bay deal... It’s more to discuss this idea that the Mets need to solely concentrate on pitching this offseason, because anybody that watched last year’s team would have to see that there was a lot more wrong with the 2009 Mets than starting pitching.

And to an extent I agree. Any rational person should agree with that statement. The Mets were broken last year, and as Chris points out, they ranked poorly in both defense (16th in runs against) and offense (25th in runs scored). Any move which, in a vacuum, makes the Mets better than before is a good move. However, he continues on to say:

The Mets focus ... should be on finding the most efficient way to outscore the competition. Pitching doesn’t win championships by itself, but putting together the best combination of hitting and pitching together does. Look at the last three World Series champions ... Run prevention is obviously important, but all of these teams could score some runs, too. None finished lower than third in baseball in run differential, and that’s with the randomness of the baseball postseason working against them.


Adding Bay helps the Mets improve their ability to outscore the competition, at least in the short-term, and for that, the move was a decent one.

Yes, outscoring the other team is the entire point. But I think that his analysis is incomplete.

With a team like the Mets, who struggled last year, and who need improvement in all areas, pitching and defense is the most important place to begin. Yes, many teams who have middle-of-the-pack pitching will succeed behind a dominant offense. But when we are talking about the marginal value of an improvement of the team, run prevention is most important. Here is why.

Take a hypothetical .500 team. They score exactly as many runs as they allow in a season. Their average game score is 5-5. By adding offense, they improve their chances of winning. Let's say they make improvements and in the next year add one run on average to their per-game total. They average a 6-5 win. Let's call this Team Offense. This team will win more games than they lose.

Take that same team, and instead of adding offense, improve their pitching and defense. If they were to lower their opponents average score by one run, they would have the average score of their game be 5-4. Let's call this Team Pitching. This team would win more games than they lose. But they would also win more games than the team that won 6-5.

Team Offense, in a season, would score 972 runs but allow 810. Their pythagorean win total would be 94, and would win 58% of their games. Team Pitching, in a season, would score 810 and allow only 648. Their pythagorean win total would be 97, and would win 59.8% of their games.

It makes sense when you think about it. Team Offense only scored 20% more runs than their opponents, while Team Defense outscored their opponents by 25%. At a lower average score, each run was more important.

Not only does this make for a better team, but it makes for a more fun baseball game to watch. Stronger pitching preserves your bullpen over a long season. Better run prevention has, time and time again, proven to be important come playoff time.

So yes, improving your team is improving your team, and the Mets are gonna be a lot better with Jason Bay next year than without him. But not all runs are created equal.

Thanks to the calculator at the Replacement Level Yankee Weblog for the actual number crunching.

1 comment:

Ari Berkowitz said...

Recently found your blog. very interesting stuff and appealing to me as a huge Mets fan, and a statistically inclined one.

You're using a flawed methodology in this post. If you win every game 5-4 you've improved your fielding more than you improved your hitting while winning games 6-5. But this is obvious. If you had a choice between Franklin Gutierrez's glove(expecting him not to regress too much) and Brad Hawpe's bat you'd take Gutierrez's glove for the sole reason of it being more valuable runs wise. But if the additional offensive output and defensive outputs were equal(and not 25% vs. 20%) it wouldn't make a difference. If you instead improved your value over your opponent's by the same 20% meaning you'd win every game 5-4.167 it would then be an equal and fair comparison.