Ruud facing Marozsan test
Shelton needing to serve well against Sinner
Korda and Hurkacz also favourites
Marozsan not to be underestimated against Ruud
We will have a clearer idea of who is likely to get through to the latter stages from the bottom half of the draw following Tuesday's action, which sees solid market favourites in each of the four matches on the schedule.
Getting matters underway at 0530 UK time is Casper Ruud and Fabian Marozsan, with eighth seed Ruud the 1.374/11 favourite to progress past the Hungarian, who should ensure a career-high ranking following this event, almost certainly guaranteeing him a main draw spot in January's Australian Open.
Marozsan has already picked up two underdog wins so far in this event and he'll need a third in order to make the quarter-finals. He's not dropped a set so far, though, so should go into the clash against Ruud with confidence. Ruud has also yet to drop a set, although after a first-round bye, he's only played matches, and both as a strong market favourite.
Ruud has struggled since the tour returned to hard court in August, only winning consecutive matches once, and losing as a favourite against opposition ranked outside the top 50 three times. So, anyone thinking this match is a foregone conclusion should think again, particularly as Ruud is 9-9 on hard court this year and barely winning over 50% of points in his matches overall.
Should Ruud be favourite? Yes. But his price looks a little on the short side to me.
Korda's serve should be the difference
Following this, Sebastian Korda is favoured by the market at 1.4840/85 to get past Francisco Cerúndolo, who wouldn't necessarily have been anticipated to thrive on a quick hard court. Korda's stronger serve should be the difference here - he's held around 7% more on hard court this year - and the market price looks very justified, particularly given that Korda is bringing a strong form line into the match.
Fatigue the key consideration for Sinner
After a break, the evening schedule sees Jannik Sinner meet Ben Shelton, with Sinner having won seven in a row and Shelton looking to continue his good form which saw him reach the semi-finals of the US Open in what was a shock run of results.
Shelton's fightback win over the in-form Roman Safiullin last time out should be viewed as a positive for his chances, although Sinner is a marked step up in level. However, there's reason to consider Sinner could be pretty fatigued currently, having a quick turnaround after winning the Beijing event and looking a little underwhelming in a three-set win over Sebastian Baez in round three.
The duo have never met before but the key for me will be how Shelton's solid serve can cope with Sinner's strong return game, which has seen him break opposition over 30% of the time on the surface this season. Sinner is 1.3130/100 to get the win, which is worth re-evaluating after the first few games of the match - for example if the scoreline is 2-2 in the first set but Sinner has made little inroads on return, there could be value on Shelton in-running.
Similar scoreline to four years ago expected for Hurkacz and Zhang
Finally, Hubert Hurkacz at 1.4640/85 is anticipated to see off the threat of home player Zhizhen Zhang. Zhang has done well of late, beating Ruud at the US Open and picking up an underdog win over Brandon Nakashima in round three, but Hurkacz will be no pushover, particularly given his strong serve.
The only career meeting between the two players was actually at this venue four years ago where Hurkacz won 7-6 6-4, and a similarly close meeting with the Pole emerging victorious is the most likely outcome.
So, four matches with four solid favourites. If I had to pick something today, it would be Marozsan on some form of handicap, with that advance in-play consideration in the Sinner versus Shelton match. However, from a pre-match pricing perspective, it all looks pretty accurate at the time of writing.