So now, Roy Halladay will try to get his Johnny Vander Meer on.

The odds against the Phillies ace throwing back-to-back no-hitters is staggering, of course, never mind another perfect game. Vander Meer never had a perfecto, but he did have consecutive no-nos for the Reds in 1938. No pitcher did it before. No pitcher has done it since.

Halladay goes back to the mound tonight at Citizens Bank Park for the first time since he retired all 27 Marlins hitters he faced last Saturday night at Florida. It's safe to say that his only focus is beating the San Diego Padres, which is how it should be.

It is interesting to note, though, that while perfect games remain rare, they're not as rare as they used to be. There have been 20 in major league history. Half of them came from 1880 to 1981, a span of 102 seasons.

There were seven in the next 25 seasons. Now there have been three in the last calendar year: Mark Buehrle for the White Sox last July and Oakland's Dallas Braden and Halladay since Opening Day. And Detroit's Armando Galarraga should have joined that group Wednesday night, only to have it snatched away by an umpire's call.

That could be a statistical oddity. Or it could reflect the change in emphasis in baseball over the years from rewarding disciplined situational hitting to a pay structure that encourages every player in the lineup to swing for the fences.

As for Halladay, the postperfection performances of pitchers since expansion in 1961 has been mixed at best. They are a combined 4-5 in their subsequent start with a 4.57 earned run average.

Braden is 0-3 since. Buehrle won only two more games the rest of the year after his mastery on July 23. Kenny Rogers lost his next two starts in 1994 and then was hurt. David Cone (1999), Dennis Martinez (1991) and Len Barker (1981) weren't the same afterward.

On the other hand, David Wells turned his 1998 season around after his perfect game. And Sandy Koufax (1965) and Randy Johnson (2004) never skipped a beat. Here's the complete list: