It’s that time of year when many GMs are deciding between acquiring pieces for the stretch run and calling it a year and selling valuable spare parts. An important part of the equation is determining how well the GM thinks his team will perform for the rest of the year. In general, teams with better records will be more inclined to buy than sell, and vice versa.
But, a raw win-loss record can be misleading. In some cases, the team that is scoring and allowing runs that would normally result in more or fewer wins may indicate that the team is better or worse than its actual record. Let’s call this Pythagorean luck (I dislike the confusing reference to the Greek mathematician, but the name has stuck). For example, the Braves this year are an unimpressive 47-52; however, the Braves have played much better than their record. They have scored 440 runs while allowing 412 runs: a combination that ought to produce a winning record of approximately 52-47.
On the hitting side, the Braves have been slightly below league average, scoring 4.44 runs per game, compared to the NL average of 4.51. It’s the pitching that has really kept the Braves playoff hopes alive. The team’s 3.81 ERA is second in the league. However, this is where I want to bring in the other type of luck a GM needs to consider.
Frank Wren, or any other GM, cannot just look at a Pythagorean W-L record and assume random run-agglomeration will even out and expect that as luck turns around that his team will be good enough to contend. The other type of luck is the random fluctuation of player performances around their true talent level—let’s call it talent luck. In the case of the Braves, I believe the pitching has performed better than its talent level and will not hold up. Hats off to Roger McDowell and the pitching staff, but I don’t think the team will finish second in ERA. Now, it is possible that the pitching will continue to be excellent as it has been, but I doubt it.
And even if the pitching and hitting continue on their current trajectories, the team still faces a significant real six-game deficit in wins to a Philadelphia team that has also played a bit unlucky: 53-46 compared to a 57-42 expected record.
I wonder if this is similar to the conclusion that A’s GM Billy Bean reached about his Oakland team. Though the A’s have outperformed their record by four wins, and the division-leading Angels have won 7 games more than the run differential predicts. Yet, Beane traded away both Rich Harden and Joe Blanton to the Cubs and Phillies, respectively.