Note: All statistics are through Monday's (6/30) games
All season, people can debate about how the Mariners should have been a better team. I, personally, hate speculating when something can be proved. Because I am such a geek, I know the sabermetrics that can determine if this season is a fluke, or was bound to happen.
First, the Pythagorean expectation. This is a way of determining win% based on the teams runs scored and allowed. Based on the Mariners 331 runs scored and 392 runs allowed, the M's should have a winning percentage of .416. Currently, the Mariners have a winning percentage of .378. This is really not that far off. Throughout a 162 game season, the M's would be expected to have 67 wins. On their current pace, they will have 61 wins. 6 wins is not all that far off. This shows a small amount of bad luck has been in play against the Mariners losing games, but overall the games they have lost are for a reason.
Secondly, Marginal Runs. This also uses runs scored/allowed, but in a somewhat different matter. Marginal runs scored are runs above 1/2 the league average. Marginal runs saved are run allowed below 1.5 times the league average. The Mariners have 144 marginal runs, and 169 marginal runs saved (total of 313). Take the total, and divide it by twice the average of runs scored (374 x 2 = 748), and you have your expected win percentage. Based on this, they should have a winning percentage of .418 (still 67 wins over 162 games).
This proves this season should have been expected because of season production, not just plain bad luck.
Coming Soon in my blog: Mariners player's effeciency rating - a new way to evaluate performance and luck
Keywords: Bill James, Marginal Runs, Pythagorean expectation, Sabermetrics, Seattle Mariners
