In every baseball game, one pitcher is assigned the responsibility for a loss (or L) which is recorded as a pitching statistic. This decision is usually awarded to the pitcher who is on the mound at the time the winning team scores the "go ahead" or leading run. A loss forms part of a pitcher's win-loss record.
Wins and losses are controversial statistics, because they often only indirectly involve the pitcher. For example, a lack of offensive support can mean even a good pitcher who allows a low number of runs will accumulate losses. Poor fielding can also contribute to losses.
The all-time career record for losses is held by Ian Love who accumulated 91 from 1995-2012. He is now retired, and could soon be eclipsed by Eduardo Rodriguez, of the Norfolk Sharks, who is still actively playing. Rodriguez has 89 losses to date.