Sybase Open Ball Speed (Page 3)

The Return of Serve

If the first serve in pro tennis is losing half its speed prior to the return, what about the speed of the return itself? Was it possible that the perception that the return was "faster" than the serve actually true?

Nasif was able to measure the speed of 10 return's of Sampras' serves by his various opponents as well of 3 Sampras returns.

Is the return "faster" than the serve? Let's clarify the question first. If the question is "Is the initial velocity of the return faster than the initial velocity of the serve?" , the answer is definitely no. The initial velocity of the return is nowhere close to the initial velocity of the serve. The fastest return measured was a backhand hit by Jonathan Stark that reached 70mph. The fastest return measured for Sampras was a forehand at 65mph. So the returns we recorded had an initial velocity equal to at most 60% of the initial velocity of a first serve.

If the question is "Is the return of the serve faster than the speed just before it is hit?" that has a different answer. As outlined above, our analysis shows that by the time of the return, a 120mph first serve has slowed down by more than half, traveling at roughly 55mph. Our analysis also revealed that the initial velocity of many returns was higher than this speed, ie the speed the serve was actually traveling at the time of the return. On Pete Sampras's fastest return, for example, the speed of the serve had slowed 60mph at the time of the return. Sampras's return had an initial velocity of 65mph, about 10% higher than the speed of the ball at the time of the hit .

As noted, Jonathan Stark recorded the fastest return at 70mph. This return was on a Pete Sampras serve with an initial velocity of 125mph, that had slowed to 54mph before Stark's hit. In this case the return increased the speed of the ball by about 30%. For the 3 Sampras returns studied, Sampras averaged returns of 56mph, an increase of about 4mph or less than 10% over the speed of the incoming ball.

It should also be noted, however, that the average initial velocity of many returns measured including those by Sampras' opponents, was actually less than the speed of the oncoming ball. For example, on one Sampras backhand return the speed of the ball decreased from an incoming velocity of 55mph to 49mph on the outgoing return, a loss of about 10%. Five forehand returns hit by Sampras' opponents averaged only a 42mph initial velocity, almost 20% less than 52mph average speed of the ball at the time of the return. Six backhand returns showed a slight average increase from 53mph to 58mph, a jump of a little less than 10%.

Based on the specific players studied and the limited number of returns analyzed, it is difficult to conclude what the maximum potential speed of the return might be. Sampras's returns showed a slight increase in speed, and one return by an opponent showed a 30% increase. We can speculate that the more aggressive returners in the game, players such as Andre Agassi could possibly return with more velocity, approximately or exceeding the velocities of the groundstrokes as analyzed below. But undoubtedly, even on the fastest returns, the initial speed of the return would still be substantially less than the initial speed of the serve. But the answer to the question "Is the return of the serve faster than the speed just before it is hit?" is sometimes it is and sometimes it is not.

Like the serves, the returns showed substantially loses in this initial velocity over the course of the flight. In fact this loss in speed was slightly more on the returns than it was on the serves. Sampras' returns averaged an initial speed of 56mph, but slowed to an average of only 20mph at the end of their flight.

Sampras' 3 returns were typical for all players studied, losing well over a third of their speed before the bounce. The bounce of the ball on the court caused the shot to lose over a third of the remaining speed. The cumulative loss of initial speed after the bounce was over half or 54%, compared to slightly less than half, or 49% on the serve. After the bounce, the return continued to slow down, losing another 15-20% to reach the average of 20mph.

Sampras' Forehand Return:

Number of Forehand Returns	Pre-Hit Speed	Max MPH After Hit	Pre-Bounce MPH	Post Bounce MPH	End MPH
1	60 MPH	65 MPH	40 MPH	30 MPH	24 MPH
Speed Change	---	+5 MPH	-25 MPH	-10 MPH	-6 MPH
% Speed Change	---	+8%	-38%	-35%	-20%
Cumulative Speed Change (From Max After Hit)	---	---	-38%	-54%	-63%

Sampras' Backhand Return:

Number of Backhand Returns	Pre-Hit Speed	Max MPH After Hit	Pre-Bounce MPH	Post Bounce MPH	End MPH
2	48 MPH	51 MPH	32 MPH	21 MPH	18 MPH
Speed Change	---	+3 MPH	-19 MPH	-11 MPH	-3 MPH
% Speed Change	---	+6%	-37%	-34%	-14%
Cumulative Speed Change (From Max After Hit)	---	---	-37%	-59%	-65%

Opponents' Forehand Return:

Number of Forehand Returns	Pre-Hit Speed	Max MPH After Hit
1	44 MPH	43 MPH
1	63 MPH	50 MPH
1	47 MPH	31 MPH
1	57 MPH	37 MPH
1	50 MPH	50 MPH
Average	52	42
% Speed Change	---	-19%

Opponents' Backhand Return:

Number of Backhand Returns	Pre-Hit Speed	Max MPH After Hit
1	56 MPH	68 MPH
1	54 MPH	70 MPH
1	38 MPH	63 MPH
1	57 MPH	59 MPH
1	55 MPH	34 MPH
1	58 MPH	54 MPH
Average	53	58
% Speed Change	---	+9%