Frankly, they are beyond the bounds of believability. http://www.baseball-reference.com/teams/LAA/2010.shtml Through 17 games, Peter Bourjos has a TotalZone rating of +11, which breaks down as +4 for his outfield assists, and +7 for his range. That kind of rate cannot be maintained, it would mean he'd save something like 100 runs per full season. But has he saved 11 runs so far? You look at the plays, count them up, and it seems about right so far. Last night he saved 3 with a catch that turned a 3 run homer into the third out of the inning. Earlier he just missed another, turning a homerun into a double off the heel of his glove (nobody's perfect).
Before last night's game he had 16 games, 54 putouts, and 4 assists. If any outfielder really could keep up that pace, racking up 540 putouts (400 is a good total for a CF) and 40 assists (Even Clemente never did that) in a season, he probably would be saving that many runs. Speaking of the 4 assists, Torii Hunter had that many in the entire 2008 season, and another 4 for 2009-2010 combined. This Bourjos kid is something special in the field.
So far, looks like another Devon White. Let's be very patient with his bat, and not dump him so he can help somebody else win world series titles.