Alpha? Omega? The recent controversy about Caroline Wozniacki’s impersonation of Serena Williams got me thinking about the history of impersonating a player’s ticks or idiosyncrasies. My mind initially thought that Jonas Bjorkman was the progenitor of this fad. His rain delay US Open fodder of lighthearted imitations did indeed pave the way to Djokovic’s 2007 US Open impersonation tour….