Madrid Masters Day 7: Can Anderson's head to head lead be trusted?

semi-finals take place, and our tennis columnist, Dan Weston, is back to discuss the two matches...

Nadal steamroller derailed by Thiem

50 and out - not the rules of a backyard cricket match, but Rafa Nadal's clay record, as his 50 set unbeaten run was halted by Dominic Thiem in straight sets. Thiem ironically was the last man to beat Nadal on clay, in Rome last year, and is now the man who prevented him from going a year unbeaten, without dropping a set, on his favourite surface.

Thiem's reward is a semi-final clash with Kevin Anderson, with this match kicking off proceedings at 15:00 UK time in the Spanish capital.

Anderson head to head lead worth debating

The first thing I noticed when looking at this match-up is the absurd head to head lead that Anderson enjoys over his Austrian rival, with the big-server winning all seven meetings. However, one was in an exhibition match, and two were when Thiem was not even close to the top 20, so we can at least discount them and consider it to be a more realistic 4-0 record.

None of these were on clay, but they all were played at venues which I would not grade as playing particularly slow, and certainly Madrid falls into this category as well, being the quickest clay court on the ATP Tour. The question is this - how much relevance do we give this Anderson head to head lead? It's a tough question to answer, but I'd lean towards not a great deal.

Value on Anderson depending on head to head lean

Market prices have Thiem as a strong favourite at 1.41, with Anderson a 3.35] underdog, and my model made this a little value on the South African, but not enough to warrant recommendation. Regarding a recommendation for this match, it really boils down to whether you think the head to head record has some relevance to this future match-up. If so, then you may wish to avail yourself of this price on Anderson.

Zverev a heavy favourite to defeat surprise package Shapovalov

Following this match, Alexander Zverev is a heavy 1.25 favourite to make the final, as he faces Denis Shapovalov, who got the better of Kyle Edmund in three sets yesterday. Shapovalov had no record on clay whatsoever prior to this week but is obviously on an upward curve in his career.

However, the Canadian's performances this week have been influenced by him taking his chances - he's converted 47.8% of break point chances in Madrid, which is vastly bigger than his 35.7% return points won percentage. Historical player analysis shows that it's very difficult to maintain such a 'clutch' ability, and perhaps he's over-performed a little this week.

My model largely agreed with the market pricing in any case - Zverev's level (119.4% combined serve/return points won percentage) this week has been exceptional and it would be very surprising if the German did not make tomorrow's final.