In the wake of Johan Santana's three-hitter, Bob Klapisch offers a wonderful explanation: Santana has stopped tipping his changeup:

Like any veteran with a killer pitch (and an ego to match) Johan Santana wouldn’t admit hitters had cracked the code on his changeup. Was he tipping the arrival of that 81-mph illusion? It sure seemed that way, although Santana had trouble believing it.

Still, the evidence was mounting almost as quickly as his ERA. The reality was practically staring Santana in the face two weekends ago, when his former team, the Twins, forced him to throw 41 pitches in the first inning. Santana got exactly one swing-and-miss, which was enough of a red flag for the Mets to begin investigating.

Turns out the give-away was the action of Santana’s glove as he began his windup: the fingers would flare as Santana dug into the leather to grip the change, which required him to make an A-OK configuration with his hand. The glove, however, remained still as Santana prepared to throw the fastball.

--snip--

Santana surprised Mets’ officials when he told Minnesota-based reporters that he still was recuperating from last September’s elbow surgery. That was the first time he’d admitted to any physical deficit, perhaps as a way of deflecting attention away from a sexual assault claim made by a Florida woman.

Santana’s honesty about his elbow, belated as it was, seemed to explain everything, especially the fastball which, until the last two weeks, had been under 90-mph for the first time in his career.

--snip--

All Santana has to do is maintain that glove position. That, and keep the fastball in the low 90s. Jerry Manuel said “it’s a real good sign” that the left-hander has been able to transition to a new delivery so quickly.

There's little doubt about Santana's declining fastball. When he pitched for the Twins, he averaged in the 92-93 range. Since joining the Mets, that figure has dropped to 91.2 to 90.5 to 89.4 this season. Santana can certainly survive when throwing sub-90 fastballs ... but of course the Mets are paying for more than mere survival. He'll probably never win another Cy Young Award because he'll probably never throw 93 miles an hour again. Not regularly. But 91-92 should be good enough to get him back on the Hall of Fame path.

But that's not really what he's doing, yet. Yes, Santana's fastball has been up in his past few starts ... but only because it was so far down in his previous few starts. He's averaged 89-90 in his past three games after being 86-87 in three of the four before those.

Obviously, 90 is better than 86. But I'm not buying until he's routinely in the low 90s, as he was last year before the elbow injury that knocked him out in August. Then the changeup, coming as a surprise once again, will work all that much better.