The grandson of tennis legend Bobby Riggs was sentenced to 20 years behind bars for sexually abusing two girls he was teaching while he worked as a coach in Florida. Daniel James Riggs, 33, was handed a 240-month federal prison stint after he pleaded guilty to coercing and enticing two minors to engage in sexual activity, the US Attorney’s Office for the Southern District of Florida announced Tuesday. Riggs, who worked as a coach for “Team Riggs” at a Fort Lauderdale tennis center, was