It happens all the time. Reporters and beat writers print articles about a pitcher developing a new pitch or tweaking their mechanics, which in turn makes them a brand new pitcher, typically new and improved. Back in mid-July, Geoff Baker of the Seattle Times wrote about Carlos Silva and his grip on his sinker:
It turns out, Silva made a between-starts mechanical adjustment. Pitching coach Mel Stottlemyre, an ex-sinkerballer himself, felt Silva was squeezing the ball too hard. So, instead of holding his hands up near his chest as he began his windup — which Silva felt caused his arms to press together and his fingers to grip the ball tighter — he held them at waist level tonight.
The writer's of USSMariner took that claim on to show that the reality of the situation wasn't matching the explanation. That, in truth, there probably was no change from any purported mechanical change. That Silva was sinmply experiencing better luck and getting better results. You can read the full post here.
We've seen this happen with a Cardinals' pitcher as well. A quick google search locates these spring training articles (I and II) that layout Pineiro's tipping pitches from last year among other foibles. Now let me add the same caveat from the USSMariner piece -- I like Goold and Strauss; I think they are good reporters. I also think that the players and coaches they are quoting are wrong as to the reasons for success or improvement and are trying to assign reasons to random events.
In the first piece, you'll find some gems:
"The key to him giving us more innings is pitching more aggressively," Duncan said. "I feel confident he will pitch more aggressively because he will use his fastball more. Last year we saw a guy who had gotten away from his fastball."
In 2005 & 2006, Pineiro threw his fastball 55% of the time. In 2007, prior to joining the Cardinals he threw the fastball 55% of the time. Hmmm. . . that seems the same to me. Pineiro started throwing the fastball 57% of the time since joining the Cardinals but that's a difference of about 60 fastballs over the course of a season or 2 more fatballs a start. Hardly a substantial increase at all.
Pineiro typically raised his glove higher during his delivery when throwing a breaking pitch while keeping it closer to his belt before a fastball. The solutions calls for Pineiro to initiate his delivery with a higher glove position.
So for all that pitch tipping that's now corrected, Pineiro has a FIP this year of 4.50 compared to a career FIP of 4.37. He is what we thought he was.
In the second piece, we find some more assignment to pitch tipping. In this case, it's with regards to Wellemeyer. As I've noted before, the real change is something measurable. He's throwing more strikes this year and, as a result*, he's reduced his walk rate considerably. His walk rate this season is half of what it was prior to joining the Cardinals. As we approach 150 innings, there's a more plausible rationale that this is a statistically significant change rather than a mere blip (see Franklin's walk rate last year).
Of course, Wellemeyer walked a few more batters last night (just to screw with me, I'm sure) and only threw 59% of his pitches for strikes but continued to be very difficult to hit allowing just 2 over 7.2 innings turning in a superb outing. The Cardinals have discovered/stumbled into a pitcher who has seemingly made a significant improvement in his skillset and he'll be under team control for a few more seasons. I was surprised by the improvement in May. I'm surprised by it now but so long as he's throwing strikes he'll likely continue to be decent mid-rotation pitcher. Let the players/coaches/scribes attribute it to whatever they want -- he's a good pitcher right now in a measurable way and that's enough for me.
*It should be noted that this could be correlation and not causation. It seems the most likely answer but in an article about subscribing to false or unsubstantiated reasoning, I'd be remiss hypocritical in not noting that.