Novak Djokovic went into the US Open with doubts over his fitness and form. He lost in the first round of the Olympics in Rio and then had to withdraw from the Cincinnati Open with a recurring left wrist injury.
All the while, Andy Murray won Olympic gold in the middle of a 22 match winning run, having won Wimbledon earlier in the Summer. Those factors led to Djokovic being unusually priced at 7/4 to win the tournament before playing his first match.
After coming through the first week at the US Open with the minimum of fuss, granted with a couple of retirements, he is now the best priced 6/5 favourite. This is mainly down to his fourth round match last night, in which he beat Britain's Kyle Edmund convincingly in straight sets.
Edmund himself has been in great form, beating John Isner and Richard Gasquet in his run to the fourth round, so this match really seems like the signal to bettors that Djokovic is back to somewhere near his best.
That has been reflected in the past 24 hours on Oddschecker, with 33.5% of outright Men's US Open bets going on Djokovic. He has also attracted 56% more outright bets than Andy Murray in the same period.
If you compare that with the week between 29th August and 4th September, Murray attracted 16% more outright bets than Djokovic, which is a 49.5 % swing. It would appear that the public's confidence is back with Djokovic and should only grow further if he continues to sail through the tournament. Odds of 6/5 certainly looks like good value to those people thinking Djokovic is back to his best after last night's excellent performance.