Roy Halladay has been fantastic for the Phils for most of the season, but a little less dominant over his last couple of outings. Over his last five starts he’s thrown to a 4.41 ERA with a 1.27 ratio, allowing nine home runs over 34 2/3 innings while opponents have hit .297 against him.

In his 26 starts before that this season he pitched a 2.16 ERA and a 1.03 ratio while opponents on-based .269 against him.

So he’s slowed down. Maybe it’s nothing, but if you’re looking for stuff to worry about you would probably come up with 1) this is the fifth straight season in which he’s been in the top five in his league in innings pitched and 2) he doesn’t have a history of pitching in the playoffs.

So should we be worried about what Halladay has left for the rest of the regular season and (hopefully) the playoffs? If you need to, but I think there’s a lot of evidence to suggest that Halladay can handle the load. Even given the huge number of innings Halladay has thrown in his career, his regular season numbers in September and October are even better than they are in the earlier months of the season.

Here’s what opponents have hit against him in September and October and compared to the rest of the year for his career:

September/October 1431 235 275 343
Before September/October 7938 258 300 382

So he’s been better in all three of those categories. He also has been more likely to strike batters out after the start of September and less likely to give up home runs. Over his career he has struck out about 19.2% of the batters he’s faced in September and about 18.0% of the batters he’s faced before September. 1.6% of the September or later batters have homered compared to 2.2% of the pre-September batters.

And his career ERA after the start of September is almost a run lower than his career ERA before the start of September:

  IP ERA Ratio

356 2.50 1.08
1925 1/3 3.49 1.20

So he has actually been a lot better after the start of September in his career than he has before the start of September. Past performance is no guarantee of future results, but in this case they sure seem to suggest he may be able to overcome the 4.79 ERA he has thrown to in three September starts this season and finish strong.