The catcher is usually the first to notice the tendencies, quirks, and peculiarities of each home-plate umpire. Some umpires favor high strikes, pitched balls that are technically above the strike zone but appear, to the umpire, to be good. Conversely, some umpires will call low pitches strikes even when they are slightly below the knees. Other umpires have an inside bias or an outside bias; some umpires have more than one bias; some are uniformly lenient; some have very restricted notions of the strike zone, and the pitcher will constantly feel that their pitches are unfairly judged. The catcher can exploit an umpire's tendencies by taking them into account in when receiving the ball.