The United States and red clay don’t go together better than oil and water on most occasions.  But the ATP 250 tournament in Houston is an exception.  Many Americans use this tournament to adjust to their least favorite surface before leaving home soil for Europe.

Top half:  Defending champion John Isner spoke at Indian Wells of his hopes to become a more consistent contender this year on all surfaces.  High on his list of goals for this year is improving his results during the European spring and summer.  Back in the top 10 after reaching the Indian Wells semifinals, Isner holds the top seed in Houston.  He always plays his best tennis on home soil and will hope to build clay momentum this week for more notable tournaments ahead.  Former Houston champion Lleyton Hewitt won two of their three meetings in 2013, so a quarterfinal matchup with the Aussie looks ominous.  Also, wildcard Rhyne Williams took a set from Isner in February. 

Last year’s Houston final saw Isner solve Nicolas Almagro, who fell to him again in Miami two weeks ago.  If he sets up a semifinal rematch, Almagro might have compiled some experience in blunting big serves.  Another former champion in Ivo Karlovic looms above his section, while Jack Sock can project plenty of power.  A prequel to the first-round match between those men came in Memphis, where the indoor hard court rewarded their first strikes more than the outdoor clay might. 

Bottom half:  While Americans play a prominent role in the top half, Spaniards enter the spotlight in the bottom half.  Second seed Tommy Robredo fell short of expectations during the South American clay swing, so he would benefit from a solid effort before the Road to Roland Garros begins.  A 2013 quarterfinalist in Paris, Robredo could meet compatriot Feliciano Lopez in the quarterfinals.  Although both men hail from the same nation, the fast-court style of net rusher Lopez contrasts with the slow-court play of baseliner Robredo.  Alejandro Gonzalez adds a dash of intrigue after he won a set from Novak Djokovic at Indian Wells.  And nobody ever knows what to expect from Marcos Baghdatis.

A cluster of lesser home hopes hover near Fernando Verdasco, a threat on clay during his prime.  The second-ranked Spanish lefty might square off with NCAA star Steve Johnson.  Verdasco reached a final on clay last summer in the wake of his surprise run to the Wimbledon quarterfinals, but he has achieved little at most tournaments since then.  A semifinalist in Houston last year, Juan Monaco also has left his peak period far behind him.  Opportunity knocks for a surprise semifinalist from this section, perhaps Johnson or compatriot Denis Kudla.

Morocco is the only African nation to host a professional tennis tournament.  The largest city in Morocco, Casablanca perches on the coast of the Atlantic Ocean about 200 miles southwest from the Strait of Gibraltar.  After Casablanca hosts an ATP event this week, the historic inland city of Marrakesh will welcome a WTA tournament in two weeks.

Top half:  Hailing from the opposite tip of the continent, Kevin Anderson reached the final in Casablanca last year.  The lanky South African wields a serve-centered game much more suited to hard courts than clay, but he does arrive in Morocco with plenty of momentum.  Anderson reached two finals in February and upset Australian Open champion Stanislas Wawrinka en route to an Indian Wells quarterfinal.  An early challenge might come from Federico Delbonis, who fell just one point short of an ATP 500 title on clay last year.  That Hamburg run, which included a victory over Roger Federer, presaged the Argentine’s 250-level title in Sao Paulo during this season’s South American clay swing. 

Spain lies across the Strait of Gibraltar from Morocco, making Casablanca an easy trip for players from that nation.  Among them is Marcel Granollers, a quarterfinalist in Rome last year.  Granollers has acquired a stronger reputation in doubles than singles, and he has won just four of 12 matches in 2014.  The Spaniard has landed in a soft section, where his most intriguing test might come from a compatriot.  Early last year, Pablo Carreno-Busta turned heads with a long winning streak at the Challenger level and an ATP semifinal on Portuguese clay.   By contrast, he has lost eight of nine matches in 2014, although he was unfortunate to draw Robredo in the first round of two clay tournaments. 

Bottom half:  Part of this weekend’s Davis Cup tie, Gael Monfils took a wildcard into Casablanca to gain some early clay preparation.  Although Monfils has reached a semifinal at Roland Garros, his ebbs and flows in focus can cost him on this surface.  Near him lurks Leonardo Mayer, who reached a South American clay final this spring after upsetting Robredo.  But Mayer faces a difficult first-round test against Jiri Vesely, a rising Czech with a near-upset of Andy Murray at Indian Wells to his credit.  Portuguese clay specialist Joao Sousa will look to avenge a loss to Monfils on French indoor hard courts last month.

The latest enigmatic Frenchman to emerge in the ATP is Benoit Paire, sometimes projected as a future top-10 star.  If he aspires to that height, he must find greater consistency and patience than he has shown so far.  One of the rare men who prefers his backhand to his forehand, Paire might meet a Spaniard who routinely runs around his backhand to hit forehands.  Guillermo Garcia-Lopez has earned his best results on hard courts, like Paire.  The uncertainty surrounding this section might allow an unseeded clay specialist, such as Carlos Berlocq or Albert Montanes, to break through.