Hideki Matsui of the Oakland Athletics found his stroke after the all-star break. After a 4 for 6 on Thursday, he's hitting .432 after a .209 first half. His pitch selection improved, as you can see in his swing rate.
Early in the season, Matsui seemed to chase pitches up and in:
Note how his swing zone is vertical, as if pitchers were working him up the ladder. The up and in area of the strike zone indicates he was swinging at pitches that were jamming him. He wasn't making great contact:
When he swung at pitches in the middle of the zone, he often missed them.
His swing selection became more horizontal in the second half:
He's now picking a level, and staying in that zone, rather than following pitches up. His contact rate improved:
He was missing on 18% of his swings before the All-Star break, only 10% after. Matsui swings at better pitches, makes better contact, and his batting average is reaping the benefits.