Strategy of efficiency. Tell me which you would rather do:
swim 46 seconds 50s (x10) with dolphin kicks and pullouts. (7:40)
or take out pullouts & dolphin kicks and
swim 47 seconds 50s with 10 to 12 fewer kicks and two extra breath per 50 m? (7:50)
(100-120 kicks less + 20 extra breaths?) Still swimming sub 8 min?
Mastering the CSS is more than just "pull-breathe-kick-glide".