This is not a Wawrinka thing, or even a U.S. Open thing.

A hidden dynamic of tennis is that the longer the point develops, the more even the outcome naturally becomes, no matter how good a player is perceived to be at grinding away from the back of the court. Even Novak Djokovic, considered a Superman in long rallies, lost more points than he won in rallies of nine shots or more during his U.S. Open title run last year.

It might be time to update the term “consistency” in tennis so that it doesn’t lead players down the wrong path in practice, where they think they will win more matches because they hit tens of thousands of groundstrokes crosscourt and down the line.

Wawrinka has been very “consistent” at the beginning of the rally, at putting two consecutive shots in the court. The old way to develop consistency on the practice court is to hit 20 balls in a row without missing, and then repeat that four times. A better strategy, which meshes more with the reality of a match, is to focus on the serve, the return and the shot after the return; put just two balls in the court in a row, which equates to a four-shot rally, and do it 20 times.

The first phase of a rally is far more difficult to traverse than the end, with the serve and return yielding a higher percentage of errors than rally forehands and backhands.

In the men’s tournament at the Open for the past four years, 88 percent of the time the match winner also won more points in the 0-4 shot rally length. In that same span, match winners won the nine-plus shot rallies just 53 percent of the time on average.