Coaches should be flexible regarding positioning. Important factors in positioning are physical fitness and anticipation. Physical fitness or the lack of it is usually obvious but the co-ordination of what an umpire is seeing , the anticipation of play movement and the physical reaction required only comes with experience. Lack of concentration Lack of concentration affects the whole gamut of umpiring. Positioning, reaction speed and reading of advantage are probably the most important.
Umpires vary in attention span levels.
Lack of concentration can be caused by a variety of reasons. An inflated idea of one's ability Lack of concentration can be indicated by inattention, slow reaction time, interest in things occurring off the field and the time gap between blowing the whistle and signalling. Inability to handle stress Indicated by over reaction to incidents. Can be cured by knowledge, experience and good coaching. Body language is a good indicator.