Imagine if tennis had the equivalent of a heavyweight championship boxing belt (in addition to all the other current trophies on offer) where it gets passed on from winner to winner. To simplify things, I will take the winner of the USO (the last slam played) as the starting point. Murray is the reigning heavyweight champion of tennis (being the 2012 USO winner). Raonic beats Murray in the SF in Tokyo to become the new heavyweight champion. Nishikori beats Raonic in the final in Tokyo to become the new heavyweight champion. Querrey beats Nishikori in R2 in Shangai to become the new heavyweight champion. Berdyech beats Querrey in R3 in Shangai to become the new heavyweight champion. Djokovic beats Berdyech in the SF in Shangai to become the new heavyweight champion. Querrey beats Djokovic in R2 in the Paris Indoor and regains the heavyweight championship. Llodra beats Querrey in the QF in the Paris Indoor to become the new heavyweight champion. Ferrer beats Llodra in the SF in the Paris Indoor to become the new heavyweight champion. Federer beats Ferrer in RR2 of the WTF to become the new heavyweight champion. Del Potro beats Federer in RR3 of the WTF to become the new heavyweight champion. Djokovic beats Del Potro in the SF of the WTF and regains the heavyweight championship. Djokovic successfully defended the belt against Federer in the WTF final. I hope I got the above sequence right. It was a tedious task following the sequence of matches for just 3 months, let alone a whole year. Wherever Djok plays next, that’s where and when he will have to defend the belt again. If for whatever reason Djok could not play the AO, his AO title would be lost but he would still hold onto the heavyweight championship. Just some basic assumptions: Only official matches count, no exhibitions. Official matches includes Davis Cup and Hopman Cup. Singles only. Excludes matches like the Kooyong Classic. Official matches can be BO3 or BO5.