What is the difference between ERA and WHIP?

ERA is the earned runs a pitcher gives up per nine innings — the damage on the scoreboard. WHIP is the walks and hits he allows per inning — the traffic on the bases. A pitcher who strands runners, or whose defence turns double plays behind him, can carry an ERA a full run better than his WHIP says he should; over a full season the two tend to meet. WHIP also ignores whose fault a run was, which is the judgement call inside every ERA.

ERA (ERA) in fullWHIP (WHIP) in full