Chicago Cubs left fielder Ian Happ was averaging one home run per month this season at the start of June. Happ added his fourth on June 5, and suddenly the balls he hits are going out of the park with a little more regularity. “When you’re sitting there in the middle of May with three homers, you’re definitely frustrated,” said Happ, who hit 25 last season. Happ has hit eight homers this month.