Kei Nishikori is a dominant Tempo player. Taking all the ball on the rise he generates pace on every shots. As a very agressive baselined he can be dangerous with the forehand, the backhand and also the return.
Tempo / Very high
Kei Nishikori comes in more and more and in total 16% of his points are won at the net (with or without a volley to play). We can't regard him as an Offensive player but he knows when to move forward to get an edge.
Offensive / Medium
If we have to point a weakness in Kei Nishikori's game, it would be the Serve. When compared with his rivals he makes on average 40% less aces/service winners than them and his ratio of unreturned first serve is below average (26%).
Server / Low
Although Kei Nishikori is more a Tempo player than a Puncher, his topspin forehand is excellent and it allows him to accelerate slower balls with ease. Capable of playing with Tempo or Punch, he is a complete aggressive player from the back of the court.
Puncher / High
Kei Nishikori is also very effective when the rallies extend over 8 shots. We can't say that he is a Retriever because his Tempo & Punch quality dominate his game style but he can also win points by the errors of his rivals. In total, 44% of his points are won this way which stands in the average of the ATP players.