Guerrero hit 91 home runs to 57 for Alonso and I agree that having to hit so many home runs to reach the finals wore him down, (although he still hit 22 homers). But there was more to it than that. Pete had another advantage: he always went second and knew exactly how many home runs he had to hit to advance. He hit that number and the round was over, so he stopped and saved his swings. Which was a disadvantage in terms of his total home runs: if he'd taken the remaining time, including the 30 second bonuses, he'd have hit more total home runs.
The fact that he didn't need to participate in "slug offs"
meant the same thing. Finally, Pete, like the greatest power hitters, is a spray hitter: of his 30 home runs this year, 8 have been to left field, 6 to left center, 6 to dead center, 8 to right center and one to right field. Guerrero is a pull hitter: of his 8 home runs since he got called up are to left, 2 to left center and 4 to center field. it looked like all his homers last night went to left. That gave him a shorter target. Pete kept hitting to center and right center and coming up short. if he ever learns to pull, some records will be broken. As it was, (and with the quality of throwing- you can't call it pitching) to him, it has hard for him to get a run of homers going. But he persevered and caught Santana, Acuna and Guerrero.
It would be nice to know the average distance of Alonso's home runs - the best I could get from looking at 3 Google pages of articles was that he averaged 421 feet in the final round. I was able to find that Guerrero averaged 424 for the entire contest and had the longest one, 488 feet.
As impressive as Guerrero's home run total was, saying he deserved to win is a bit like saying that the team that scores the most points in the NCAA tournament is the national champion.