If you haven't been paying great attention to Baseball Tonight, you may have missed that Bobby Jenks tied a major-league record today by retiring his 41st consecutive batter.
Folks, that's a hell of a streak. Analysts sometimes bring up "hidden perfect games" thrown by starting pitchers: a streak of 27 or more consecutive batters retired across two starts. Obviously hidden perfect games aren't as sexy as the real thing, but they're generally just as difficult a feat.
What about Jenks' streak? It's even more special than a real 27-up, 27-down performance. Let's say that a good starting pitcher can safely retire 71% of the batters he faces, and a good reliever 74% (because it's easier to pitch in relief). How often will the starter throw a perfect game?
(1 - .71)^27 = .0096%, or roughly once in 10376 starts
How about the reliever retiring 41 straight?
(1 - .74)^41 = .00044%, or roughly once in 229879 such streaks
Basically, we're seeing something 20 times as rare as a perfecto. Considering fewer than 20 perfect games have been thrown in history, that's really something.
Edit: This is technically not true, because the consecutive batters retired streak can start anytime, while a perfect game must include 27 specific batters. But it does give you an idea of how uncommon Jenks' streak really is.