
Granted, his BA is streaky, but the other numbers he puts up really aren't which more than make up for his inconsistant BA.
Ever since Giambi missed most of the 2004 season due to complications from admitted steroid and HGH abuse, his home runs have also been streaky. He'll go on tears will he'll homer is just about every other game, but then he'll go on multiple 3-week long homerless droughts.
Taken in context with the fact that his power was so depleted in the first half of the 2005 season (5 HR in first 187 AB) that the Yankees wanted to send him to the minors, it's suspicious that Giambi was suddenly able to hit 11 HR in his next 50 AB (after the threat of the Yankes demoting him to the minors came out).