There have been numerous occasion where Dhoni looked more of a captain then current skipper Virat Kohli. However, most of the time it down to him the keeper, like most of the wicket-keepers, Mahi is always giving tips and instruction to bowlers on how to deceive the batsman.
In the second ODI against New Zealand in Pune, it became evident yet again as the stump mic caught some of his suggestions for the bowlers. The instruction showed how he analyses his opponents and has a plan for the batsman.
Well, after 300 ODIs, one cannot doubt or question as to how much of a cricketing brain he has.