We're a bit up and down this tournament and the last round was definitely down. Jo-Wilfried Tsonga was back to his frustrating worst while Kevin Anderson was a shadow of the player who beat Andy Murray. It was sad to see Petra Kvitova struggle so badly in the heat after the first set of her quarter-final against Flavia Pennetta but that was always a risk given her glandular fever and, with hindsight, that was not a good bet.

The only positives to take are that my outright picks are going well with Simona Halep and Roger Federer both one match away from netting profits.

Onwards and hopefully upwards and Roberta Vinci faces the daunting task of stopping Serena Williams in the women's semi-finals. Williams is well and truly in the groove and, after repelling her sister's challenge on Tuesday, this could be a short night's work. The banker is Williams -6.5 games on the handicap but it's definitely worth playing her to win the opening set 6-0 and 6-1 with the odds looking generous from here.

Halep's quarter-final with Victoria Azarenka saw tennis of the highest quality with the Romanian showing no sign of the leg injury which affected her against Sabine Lisicki. Her semi-final opponent Pennetta merely had to keep the ball in play and wait for the errors from the stricken Kvitova's racket, but that was a long hard match in the heat and she had to play doubles last night too. The world number two doesn't make many unforced errors, she runs down everything and she could be Pennetta's worst nightmare. I expect Halep to win in straight sets and 9/10 is more than fair.

Novak Djokovic has a superb recent record against Marin Cilic but the defending champion is definitely playing himself into form. And with the world number one a little below his best this fortnight, I'll have a dabble on Cilic to win a setat even money.

I won't be playing in the remaining semi between Federer and Stan Wawrinka. Federer is the only player not to drop a set so far and he looks like a well-oiled machine. But Wawrinka sparked into life last night against Anderson having looked a little disinterested previously and was clinical against the misfiring South African. If he can get Federer out of his rhythm early on, it could be a superb match.

Serena Williams -6.5 games v Roberta Vinci - 2pt @ 5/6Lost 2pt
Williams to win first set 6-0 - 0.75pt @ 12/1Lost 0.75pt
Williams to win first set 6-1 - 1pt @ 9/2Lost 1pt
Simona Halep to beat Flavia Pennetta in straight sets - 2pt @ 9/10 - 2pt @ 9/10Lost 2pt
Marin Cilic to win a set against Novak Djokovic - 1pt @ 1/1Lost 1pt