Counting for Focus

I also hear complaints from some new students that it is too distracting to count. Yes, counting with part of the brain will take up some portion of the limited attention resources for those not used to it, and for those who have to divert a great portion of their attention to hold more fundamental skills in place. But stroke counting is a skill too – it may not be easy at first, but it will become second-nature to do it, if you practice doing it. We don’t add stroke counting to the beginner’s training process until the swimmer is strong enough in fundamental skills so he can afford to make some room in the attention for stroke counting. There comes a time in the training process when the data provided by stroke count will be meaningful and immediately useful to the swimmer – at that point it may be challenging to start but it will be a welcome addition.
https://smoothstrokes.wordpress.com/2014/07/12/my-head-or-my-watch/