WHEN EIGHT BECOME FOUR

It was not so much naughty as polite snooker from Judd Trump yesterday as he once again demonstrated his excellent tactical knowledge to see off Mark Allen 5-2.

Trump failed to impress early on, losing the first two frames, but made a century in the third and then turned the screw. Every time Allen came to the table the cue ball seemed to be on the back cushion.

In fact, according to the TV stats, Trump's safety success going to the interval was 100%.

It was a mature performance reminiscent of the way he played to win his first ranking title, the 2011 China Open.

Trump's reward is a quarter-final meeting today with Graeme Dott, the 2007 China Open champion.

John Higgins delivered another impressive display to whitewash Ryan Day but his opponent today, Ali Carter, is also hitting form, as he proved with his 5-0 defeat of Stephen Maguire.

Carter is clearly far happier and healthier than 12 months ago when the effects of his Crohn's disease were leading him to talk openly of retirement.

He is on a new diet and thankfully seems to be in better shape. In a snooker sense he will need to be against Higgins, who has won seven of their eight previous meetings.

Joe Perry is the only quarter-finalist yet to win a ranking title. He beat Mark Williams in memorable fashion at the Crucible eight years ago and Williams was less impressive yesterday against Ricky Walden than he had been in beating Mark Davis on the opening day.

However, the Welshman has always been adept at scrapping through matches if he has to. It doesn't seem to bother Williams as much as some other players if things go that way.

Shaun Murphy and Stuart Bingham served up an entertaining 3-3 draw in their recent Premier League meeting but someone has to win this time.

Murphy has seen 3-0 leads dramatically reduced in his two previous matches. Bingham grew stronger while Jamie Cope wilted yesterday.