At first glance, Game 6 starter Andy Pettitte has entered the metronome section of his career. For fantasy managers, that’s a level that is of borderline value in standard mixed leagues, but strong veteran value in deeper leagues.

Consider that he’s spent the last three years in the Bronx putting up a 4.05-4.51 ERA, won either 14 or 15 games per year, pitched between 194 innings and 215, struck out between 141 and 158, and put up a WHIP between 1.38 and 1.43. “Knowing” what you are going to get has sneaky value later in a deep league draft when the other owners are reaching.

Is there any reason to doubt that this 37-year old metronome won’t keep ticking? He is around the age when pre-steroid era pitchers began to decline precipitously, and there are some hints of cracks in the foundation.

His home run rate has always been a strength (0.77 HR/9 career), and with his strikeout and walk rates being only above-average (6.61 K/9, 2.83 BB/9 career), it’s fairly important for him to keep the balls in the yard. The bad news is that his home run rate has steadily been increasing in his second stint in pinstripes (.67 to .84 to .92 in 2009). The rate has oscillated like this before. He’s had three years with worse rates in his career than the number he put up in 2009. But this sort of gradual decline has not happened before. Fantasy owners may reasonably expect his second year of a 1+ HR/9 next year.

When looking at his pitch selection and the linear weights, it’s striking that he’s developed his cutter over his career and that the pitch has become more effective the more often he’s used it. That has to count as a good sign.

The bad sign in his pitch mix might be the disappearance of his slider. At one point in his career, he was throwing the pitch over 10% of the time and as recently as 2003-2004 it was averaging about +5 runs a year. Last year, the southpaw threw the pitch 0.1% of the time and it didn’t figure into his results at all according to the linear weights.

With the slider being a neutral pitch (-2.7 runs since 2005), should we be sorry to see it go? It moves less than his slider, and maybe it’s easier on his shoulder or elbow and will lead to longevity. The cutter is six or seven miles per hour faster than his slider according to one system, so maybe using the pitch more is an effort to avoid falling into a Jamie Moyer-esque “Slow, slower and slowest” pattern. That may not play so well in the American League. There are also some pitch-classification issues going on here. One system has Pettitte throwing the slider not at all, and another over 17% of the time last year. Whichever is true, the takeaway is that there is some flux in his arsenal as he ages.

Comparing him to Moyer may be overstating things. Moyer’s “fast”ball barely breaks 80, and Pettitte’s is almost ten miles per hour faster. But it does appear that there is some decline in Pettitte’s numbers and he will soon no longer be the safe late-round deep-league metronome that he has been in recent years.