Pre-match analysis: Pironkova v Zvonareva

There are some players who rely on their favourite shots to dominate opponents and win matches, others that understand the best course of action is to play the percentages and hope their opponents beat themselves by making too many unforced errors. Tsvetana Pironkova most definitely falls into the latter category as her quarter-final win over former champion Venus Williams proved.

The most common mistake anybody can make when up against a much higher ranked opponent is to force the play. Many players feel they will simply have to play their very best tennis to stand a chance of winning and then set about trying to do that right from the off.

Unfortunately, this tends to lead to shots being hit closer to the lines than they might do otherwise, groundstrokes being hit harder and a little flatter than usual, and risks been taken when none are needed, all of which tends to lead to way too many unforced errors.

So while most of the post-match analysis focused on how poorly Venus played on Tuesday by making a total of 29 unforced errors in just 17 games, which at this stage of The Championships is a criminal offence, few gave Pironkova the credit she deserves for understanding that she didn't need to bring her 'A' game to the court. She just needed to concentrate on the basics and trust in the simplicity of her game. She only made six unforced errors the whole match.

And this is something she's done well throughout the course of the tournament. She has only given away 70 cheap points in 87 games played so far, which is an outstanding ratio.

And it's also far easier to execute a high-percentage game plan when you're nervous than constantly to be trying to hit winning shots. So her style of tennis lends itself well to competing under pressure, something she will need to do once more when she takes on Vera Zvonareva in the semi-finals.

The Russian is another that has done extremely well to make it through to the last four here for the first time in her career, but she does have the sizeable advantage of having been in the semi-finals of a Grand Slam before. In 2009, she battled through to the same stage in Australia before losing to Dinara Safina.

And she will need to draw upon the experience she gained that afternoon and learn from it if she is to hold her nerve and make it though to her first major final.

She has the reputation of being over-emotional when things don't quite go according to plan, and on many occasions she's been reduced to tears mid-match. There's certainly no place for that on Centre Court with the world watching, scrutinising your every move.

And that will be the fundamental question; who will handle the enormity of the occasion best? Who will be able to execute their game plan under pressure with a place in the final of the biggest tournament in the world at stake?

Zvonareva's played some really good tennis at Wimbledon so far and her serve in particular has been outstanding. On average, almost 70% of her first serves are finding their mark and she's winning almost 80% of those points.In the third round against Yanina Wickmayer she was almost perfect in that regard. She won 94% on that day, only losing two points in the match when her first serve went in.

This is a shot that historically has caused the Russian problems. She doesn't have a particularly fluent motion and control of the ball toss can sometimes prove taxing. But so far here in SW19 it's worked a treat and if she can keep posting impressive numbers like that it should give her an edge in the semi-finals.

The other area in which she's excelled has been the way in which she's been able to get the balance absolutely right in regard to doing just enough with her groundstrokes to dictate play. Crucially she hasn't tried to do too much and, as a result, made too many unforced errors.

In fact, her ration of total winners (110) to unforced errors (59) is fantastic; and if she can keep that up it should again allow her to dominate proceedings against Pironkova.

There should be a nice contrast in styles to admire when they take to the court. Interestingly, the only previous time these two have done battle, the Bulgarian won easily 6-0, 6-2 indoors in Moscow at the tail-end of last season.

That will give her a boost but the circumstances this time around are very different. With so much at stake, it will be fascinating to see if Zvonareva can gain revenge or whether she will implode emotionally as she has done so many times in the past when the pressure has become too much to bear.