Carson, an amateur astronomer, was a close friend of astronomer Carl Sagan, who often appeared on The Tonight Show. The unique way Sagan had of saying certain words, like "billions" of stars, would lead Carson to ribbing his friend, saying "BILL-ions and BILL-ions". Carson was the first person to contact Sagan's wife Ann Druyan with condolences when the scientist died in 1996. He owned several telescopes, including a top-of-the-line unit. In 1981, the minor planet 1981 EM4 was named in his honor, 3252 Johnny. Carson was shown on a 1978 segment of 60 Minutes practicing at home on a drum set given to him by close friend Buddy Rich, who was the jazz musician with the most appearances on The Tonight Show. Gore Vidal, another frequent Tonight Show guest and friend, wrote about Carson's personality in his 2006 memoir. In 1982, Carson was found to be driving his DeLorean while under the influence of alcohol. He pleaded nolo contendere to a misdemeanor charge and received a sentence of three years' probation. Carson was required to attend an alcohol program for drivers and was permitted to use his car only to drive to work and back, without transporting any persons or animals in his vehicle. Carson was an avid tennis player. When he sold a Malibu house to John McEnroe and Tatum O'Neal, the escrow terms required McEnroe to give Johnny six tennis lessons. Carson's primary tennis teacher was Bob Trapenberg, who taught him for some time, and traveled with him to Wimbledon.

Answer this question "How did he do as a tennis player?" by extracting the answer from the text above.
Carson's primary tennis teacher was Bob Trapenberg, who taught him for some time, and traveled with him to Wimbledon.