ATP Finals: Zverev to find holes in Sock game
Roger Federer is already through, but will it be Alexander Zverev or Jack Sock that joins the Swiss in the last four of the ATP Finals?
Sock had to contend with a 4am fire alarm at his hotel on the morning of his match with Marin Cilic and later fought back from a set down to win the decider in a tie-break to give us a 21/20 winner.
Zverev gave it his all against six-time champion Federer, squaring the match by taking the second set 7-5, but came up short in the decider.
Sock and Zverev are meeting for only the third time with their two previous matches taking place around a year ago, both on hardcourts.
The German secured a 6-4 6-2 victory in the first encounter in Beijing, but Sock gained revenge two weeks later in a close semi-final on the indoor courts in Stockholm where the first two sets went to tie-breaks.
Zverev has won five titles this season, two more than Sock, and he gave us a 29/10 winner by taking Federer to a deciding set in their round-robin match, gaining 11 break points and taking two of them. Sock never got an opportunity to break the Swiss master's serve which explains why he is the 27/20 underdog.
But we've seen plenty of close encounters in London already and this may well be another one. The German youngster looks to have more energy than his rival and after the Federer match he sounded confident about reaching the last four, so Zverev gets our vote to win 2-1 at 29/10.
Cilic is already out of the tournament after his defeat by Sock and he goes into the Federer match trailing 1-7 in previous meetings. His only victory came during his run to the US Open title three years ago.
Federer has had a new lease of life since then and he won't want to spend too much energy in his clash with the Croat so a straight-sets win at 4/6 looks on the cards to ensure a perfect record from the Boris Becker group.
Alexander Zverev to beat Jack Sock 2-1 @ 29/10
Roger Federer to beat Marin Cilic 2-0 @ 4-6
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