And after his performance Sunday night in an American League Championship Series-clinching 5-2 victory over the Angels, it's clear that Pettitte still is.
"What can you say about him?" shortstop Derek Jeter said. "He's a guy you want to see on the mound in that situation. He's pitched in every big game. He's had a lot of success. You never see him fazed by anything. We have a lot of confidence in him."
Now, perhaps, they have even more. Pettitte held the Angels to just one run in 6 1/3 innings in Sunday's Game 6, striking out six and walking one. And in doing so, he passed Smoltz to stand alone atop Major League Baseball's all-time postseason wins list, with 16, also winning his fifth career series clincher to break a tie with Catfish Hunter, Roger Clemens and Dave Stewart.
"That's great, it's great," Pettitte said. "But the greatest thing is to be able to clinch this game and to help this organization get back to the World Series. That's very special for me."
Nearly a retiree after an uneven season in 2008, Pettitte has instead been one of the Yankees' most consistent starters all year long. So perhaps it's not surprising that little has changed in October. Pettitte has started three games, lasting 6 1/3 innings in all of them and allowing no more than three runs in any of them.
He has also posted a 2.37 postseason ERA, striking out 15 batters and walking just three -- a fact that helped him silence an Angels club that vexed him during three regular-season meetings.
"Pettitte pounded the strike zone today," Anaheim center fielder Torii Hunter said. "He's usually a guy who throws a lot of balls. He pounded the zone and was ahead of everybody today."
Pettitte is not a superstar, nor does he even carry the cache of some of his brethren within the Yankees' so-called core -- most notably Jeter and Mariano Rivera. But Pettitte is consistently good and consistently strong, and New York can hardly ask for anything more in October.
Pettitte is also more valuable than the numbers may suggest. Consider the mentoring he has provided for CC Sabathia, the Yankees' clear ace and the ALCS Most Valuable Player. No wonder Alex Rodriguez, another series MVP candidate, lauded Pettitte as "the glue" in the Bronx.
"He gives you a chance," catcher Jorge Posada said. "He gives you a chance to win. That's all he thinks about. He's got a great game plan and he really doesn't change anything. Going wrong or going right, he's going to stick to it."
It has worked for Pettitte 229 times in the regular season and now 16 times in October, the latter stat making the southpaw one of the game's all-time postseason greats. Ask him and he'll dish the credit off to Jeter or Rivera or Posada, or any number of his younger, less experienced but monumentally talented teammates.
Only when talk of the World Series arises will Pettitte allow himself to bask in the words.
"This is what we play for," Pettitte said. "This is what we set out for in Spring Training. Obviously, to be able to get there and to accomplish that, it's awesome. I just feel very fortunate and very blessed to be on this team."
Anthony DiComo is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.