The ATP Tour Finals begins this afternoon in London, and returning to give his thoughts on the two matches in the Borg group is our tennis columnist, Dan Weston...
"Across the last 12 months indoors, Federer has a large advantage over his Austrian opponent, winning almost 6% more service points and over 4% more points on return."
Borg group in action on day one
We have action from the Borg group today at the O2 Arena with tournament favourite Novak Djokovic facing the rank outsider, Matteo Berrettini in the afternoon clash (not before 1400 UK time) with Roger Federer facing Dominic Thiem in the night match (not before 2000 UK time). Matches commence in the Agassi group tomorrow with the player on court today having a rest day.
Improving Berrettini still a heavy underdog
In the first match today, Djokovic is a very heavy 1.141/7 favourite to get the better of the Italian, Berrettini, who has improved rapidly throughout the year in order to qualify here. To put Berrettini's improvement into context, he was ranked outside the top 50 prior to the end of April, although his record and stats indoors perhaps hasn't quite caught up with his numbers on other surfaces.
Djokovic's indoor stats truly incredible
Across the last six months indoors, he's won 69% of service points and 34% on return (103% combined) and while this possibly isn't representative of his current level, it would see him likely to struggle in such illustrious company this week. Djokovic is 117% combined in that time period indoors, winning all of his matches, and is 113% combined across the last 24 months - truly incredible figures given that my assessment is that anything in 110% is elite level.
The two players have never met, but it is very evident that there is a huge gap between the two players based on their numbers, and the market agrees. My model was in general agreement with the market lines.
Thiem's head-to-head success largely irrelevant here
In today's second group game, underdog Thiem actually takes a 4-2 head-to-head lead into his meeting with Federer, although the relevance of such a lead has to be questioned. Three of Thiem's four wins were on clay or a slow hard court in Indian Wells - conditions which suit him much more than Federer - while Federer eased to a 6-2 6-3 win here in the group stages last season.
That day, Federer was priced at around the 1.402/5 mark, and he's a bit shorter today, with the Swiss legend currently trading at 1.321/3 on the Exchange. I think the market price is a few ticks too big, but not enough to act on - however if he was priced the same as last year then I would make Federer value.
Federer with large statistical edge over Thiem
Across the last 12 months indoors, Federer has a large advantage over his Austrian opponent, winning almost 6% more service points and over 4% more points on return, so Roger's status as a strong market favourite is also very justified, and my view is that there certainly isn't much value in looking at the underdogs today.
However, there's not quite enough value on Federer either to justify any pre-match interest. If he drifted to 1.402/5 plus then that's a different issue, but not at current market lines. I expect both favourites to get their campaigns off to winning starts today.
Follow Dan on Twitter @TennisRatings