OK, I've wanted to touch on this for awhile, and with the recent struggles of Giants ace Tim Lincecum, it becomes apt.
Early on in the season I started thinking about guys with weird pitching deliveries, like Fernando Valenzuela and Hideo Nomo. These guys burst onto the scene and had success for a decent amount of time, but not as long as a Hall-of-Fame career would require. You can give Valenzuela a time from 1981-1986 in which he was clearly a dominant pitcher, but from 1987 to 1997, he started to falter and began the acquisition-roulette left-handed pitcher guy. And he was only 26 when he started to lose it.
Hideo Nomo had two great seasons with the Dodgers, beginning at the age of 25, before losing it and getting passed around for awhile, before coming back to the Dodgers and having two more legit seasons a little later.
Mechanics are an essential part of baseball, and once things get too complicated, problems will likely arise in the future. Age, injuries, and those slight differences you don't notice over time all conspire to take your perfect herky-jerky confusing motion into something that is only a parody of what it once was.
Your best pitchers of all time, like Bob Gibson, had a simple motion, something that was easy to correct if things go bad, and I imagine for Gibson it went bad very rarely (from 1959-1975 he had a career ERA of 2.91).
For awhile, the confusion works. Batters have a hard time picking up on the ball, and if you have stuff like Lincecum, then it's all the harder to adjust. But give those batters some video and some reps against you, that motion doesn't mean much anymore, and it certainly doesn't mean much if you can't even do it the same way and your pitches start to flatten out because your mechanics are all out of whack.
So, in other words, I predicted that he would begin to struggle. Anyone who comes on the scene with something unusual, whether it's a windup or a batting stance, is destined to have short-lived success. Athletes need simplicity in execution, because complicated mechanics get in the way. Now, I'm sure Lincecum will go ahead and pitch about forty no-hitters after I post this, but I don't see him staying dominant long. I know the past few games are a small sample size, but seeing his "predecessors" in unusual motions, the future doesn't look great for him for an entire career. I don't necessarily want him to fail, because guys like him are why we go the ballpark. So I hope he breaks out of it. He just may need to adjust that delivery to be more simplistic.