US Open Tips: Murray may have to go the extra mile to beat Raonic

Ready for four sets or more, Andy?
Sean Calvert looks at Andy Murray's fourth round showdown with Canadian Milos Raonic - a man in form who could trouble the Brit
Sunday's play at the US Open saw Laura Robson's excellent breakthrough tournament come to an end, but not before she'd won us another bet.
The British teenager bowed out in straight sets to Sam Stosur after struggling to find the kind of level she'd previously displayed, but she did enough to win our handicap wager and she's certainly been good to us this tournament.
Unfortunately Juan Martin Del Potro failed to win by the required amount of games to land my other wager as we head into week two in New York.
After a faltering performance against Feliciano Lopez, which he blamed on a lack of hot weather conditioning caused by going to the Olympics rather than training in Miami, Andy Murray faces a tougher assignment tonight.
Milos Raonic was in superb form against James Blake after a slow start to the tournament that almost saw him dumped out by Santiago Giraldo and Murray can't afford to play as he did for two sets against Lopez in this match.
Two of the three scheduled meetings between these players have been walkovers, so they've only actually faced each other once, which was at the tournament I was at in Barcelona this spring. Raonic won that day on the clay and on the form of their previous matches against Blake and Lopez respectively you would have to give the Canadian a strong chance of another upset.
It appears that the Olympics has done for a few players this summer and I wouldn't put a brass farthing on Murray at 1.331/3 in a dangerous match like this one, but he has been handed the substantial advantage of playing last under the lights in cooler conditions.
That is a huge boost to his chances, as playing conditions will be slower and Milos will have to serve to his absolute best level to win the match in these circumstances.
I don't trust Murray enough to back him at a short price, so I'm happy to take the overs in this one, as it looks sure to go to four sets at least. The total games mark is set at 38.5 and I'm going over that at a price of around 1.68/13.
In the women's draw today the clash between Angelique Kerber and Sara Errani looks to offer some value in backing the Italian with a 5.5 game start on the handicap.
While I expect the German to come through this one she's a little short at 1.251/4 and the diminutive Italian won't be brushed aside as comfortably as the odds are suggesting.
A much-improved player on all surfaces Errani's new found confidence has seen her dish out some convincing wins this tournament and she can stick this one out long enough to cover what looks a generous 5.5 game start.
This will be their third career meeting, with the score standing at 1-1 and although Kerber thrashed the world number 10 on a hard court last time out Errani won in straight sets on clay at Roland Garros and she's a different player to the one Kerber saw in Hobart.
These conditions will obviously favour Kerber and she should win, but probably not by as many as six games.
Recommended Bets
Back over 38.5 games in Murray v Raonic @ 1.68/13
Back Errani +5.5 games to beat Kerber at 1.845/6