Field quality is higher than expected
Usually a week in advance of a Grand Slam, players - particularly top 10 players - are mindful of accumulated fatigue and try to avoid overplaying. That isn't particularly the case this week with a number of big names deciding to get court time in Geneva or Lyon.
Included on the entry list in Geneva is Daniil Medvedev. The world number two is starting his clay season immediately prior to Paris.
Joining him in the Swiss capital are Denis Shapovalov and Casper Ruud, two players I wouldn't have expected to take part - particularly in the latter's case. He has a real chance of reaching the latter stages so overplaying this week is a danger.
Thiem still has much to prove
Also in the Geneva field, although unseeded, is Dominic Thiem. The Austrian would usually be very much looking forward to the French Open but since his injury comeback he has accumulated five consecutive losses, winning just one set in those matches - and not really against particularly high quality opposition.
In round one he faces a tricky task tonight against the inconsistent Italian, Marco Cecchinato.
Ruud the best player in the field
With the best data in the field, it's pretty unsurprising that Ruud is the pre-tournament favourite at 3.259/4, although it's interesting to see Medvedev chalked up as second favourite at 6.86/1.
Having not played on clay since this time last year, it would be a big ask for Medvedev - not a lover of clay at the best of times - to win this, but apart from the top six in the market, it's not a particularly strong field. If Thiem does start winning matches, they'll meet in the quarter-final.

Ruud, as top seed, has an interesting route out of the bottom quarter with the likes of Fabio Fognini and Federico Delbonis standing in his way, but he'd be a strong favourite against both of them and the rest of the bracket.
With Reilly Opelka in Q3, Ruud would also be a strong favourite to come through the bottom half of the draw - you can't really dispute his status as a solid pre-tournament favourite.
Norrie top seed in wide open Lyon tournament
Over in Lyon, there's an interesting dynamic with Cameron Norrie as top seed and Alex De Minaur also seeded and getting a first round bye - so there are two non-noted clay courters in the top four seeds. They're joined by Gael Monfils in his home country, plus Pablo Carreno-Busta as direct entrants into round two.
It's the Spaniard, Carreno-Busta, who is the pre-tournament favourite - he'll have to get past the likes of Karen Khachanov and Federico Coria to win quarter four - with the other seeds marginally back at around the 8.07/1 to 10.09/1 mark.
They're also joined by the likes of Holger Rune and Sebastian Baez, two improving players, at around those prices. Franciso Cerundolo is another young, and improving, player and should be a slightly bigger price when the tournament gets going and liquidity enters the market. He faces Norrie in round two, and there's the dangerous Baez, who won Estoril recently, in that quarter one as well.
Quarter two should be competed between Monfils and Rune, with De Minaur having an easy looking quarter three on paper. Pedro Martinez could be a threat to the Australian in that bracket, and looks like a decent option for those look to back bigger priced players.
If it wasn't for a run of tough defeats - albeit against decent opposition - I think Martinez would look make a nice value bet.