Fish vs. Tsonga:  Only once have they met in their long careers, a five-setter at this year’s US Open that oscillated restlessly between them.  Through most of the first four sets, Fish matched Tsonga serve for serve and forecourt charge for forecourt charge.  But the American flinched when victory loomed, signaling his uncertainty with untimely unforced errors and setting the stage for an emphatic final set.  A similar fate befell Fish in his first round-robin match against Nadal.  Thoroughly outplayed in the first set, he nevertheless stayed alert and capitalized upon a dip in the Spaniard’s form to win the second set and establish a lead in the third.  At that stage, though, the first-time entrant in the World Tour Finals looked intimidated by the occasion as he lost his serve with poor tactics and worse execution.  Although he displayed courage in saving two match points on his serve, Fish missed all but one of his returns during the decisive tiebreak and ended in the match with a badly bungled smash.  Having played himself to the brink of an unexpected victory, he could not quell his nerves but allowed the pressure to envelop him.

Far from nervous on any occasion, Tsonga falls victim to complacency rather than from a lack of self-belief.  Whereas few fail to notice Fish’s intense desire to win, many have questioned the Frenchman’s competitive steel.  More of a showman than a strategist, he swings for lines and corners with the first forehand that he sees more often than organizing a point.  So dangerous a shot-maker is Tsonga, though, that his rudimentary shot selection skills have not hindered him against most players outside the elite.  Moving surprisingly well against Nadal, Fish will need to cover the court just as assiduously on Tuesday and will want to extend rallies whenever possible.  Gifted with an excellent two-hander himself, the eighth seed gained repeated success at the US Open when he stretched Tsonga into his backhand corner and invited him to run around that weaker shot to hit forehands.  But Fish will want to maintain better depth than he did against Nadal, whose style did not punish him for numerous medium-pace, mid-court groundstrokes.  If he feeds Tsonga a steady diet of balls like those, the Frenchman will not hesitate to pummel them and charge towards the net for an acrobatic volley.

Among the keys to this match is the first-serve percentage of both players, neither of whom aims to win a war of attrition and both of whom rely on their delivery to gain free points.  Through most of his career, Tsonga has earned renown for balancing pace and accuracy with consistency in his first serve, while Fish’s delivery has hovered in a more typical range.  Against Nadal, though, his kick serve proved especially effective in moving the Spaniard off the court from the outset.  Another key to watch lies in the court positioning of both players, who will want to cling closely to the baseline in order to exploit any opportunities to move forwards.  Inclined to passivity when not at their best, Tsonga and Fish should seek to exploit the indifferent passing shots of both opponents by forcing the issue as often and as soon as possible.

The loser of this match almost certainly faces elimination at the round-robin stage, while the winner will live to fight another day but will need to defeat either Nadal or Federer to advance.

Federer vs. Nadal:  Arriving at the same destination, the two former poles of the tennis universe took the divergent routes that have characterized their rivalry.  Littered with service winners, rapid holds, and brisk sallies into the forecourt, Federer’s three-set victory lasted just 88 minutes.  In just a few minutes short of three hours, by contrast, Nadal eked out a series of deuce games, salvaged strings of break points, and battled through rally after rally of a dozen strokes or more.  As with their previous 25 encounters, therefore, the player who imposes his tone and tempo upon the match should seize the initiative.  Winning all three of their meetings this year and nine of eleven since the start of 2008, Nadal has forced Federer into the prolonged groundstroke duels that he favors more and more over the years.  In the sets that the Swiss master has won from him recently, such as the third set of the Roland Garros final this spring, only the most ruthless aggression and pinpoint accuracy could frustrate the Spaniard.  Observers have wondered whether any player, even one of Federer’s spine-tingling genius, could maintain that level throughout an entire match.  And routs unworthy of their rivalry now can develop when the aging legend’s artillery misfires, such as in their Miami semifinal and the fourth set of their Roland Garros final.

Nevertheless, three of Federer’s eight victories over his nemesis have occurred at the calendar’s final tournament.  Although fast indoor courts have played a role, his dominance over Nadal here stems less from the surface from the season.  While Federer has flourished in the fall with 19 career post-US Open titles, Rafa has collected just three such crowns (one since 2005) as he normally limps towards the end of an exhausting season.  This year has proved no exception but rather has accentuated the trend, with the Swiss sweeping through a Basel/Paris double and the Spaniard skidding to a Florian Mayer loss in Shanghai before withdrawing from Paris.  Within the broader narrative of Nadal’s dominance in their rivalry, therefore, lies this oasis of relative safety for Federer—so far.  In last year’s final, his title defense grew perilous when Nadal extended him to a final set, but then fatigue from a protracted semifinal contributed to the emphatic restoration of the ancien regime.

Especially notable from that match, though, was the unexpected boldness of Federer’s backhand, which so often betrayed him against Rafa.  Delivering for him on key points, that elegant shot crackled with a venom that seemed to surprise the Spaniard and made the Swiss forehand even more lethal.  If he can recapture that confidence in his weaker groundstroke, Federer likely will prevail once more on a surface that blunts the notorious Nadal topspin.  Still, he lapsed into an erratic passage after opening his first round-robin match with authority, although timely serving allowed him to recover.  More likely to capitalize upon a momentum shift than Tsonga, Nadal withstood steady pressure on his serve throughout the second half of his more arduous victory.  His level of execution may have suffered from a lack of tournament preparation, but his shot selection remained keen and his backhand fiercer than for much of the second half.  Unless Federer enjoys a spectacular serving performance, not a totally implausible prospect, their 26th meeting should hinge upon which backhand buckles sooner under the pressure of the opponent’s forehand.  A key question to ask:  which player will run around their backhand to hit forehands more often, a dangerous strategy on this fast surface?  And will Nadal gain more comfort from his dominance over Federer than he loses from his lack of dominance on this type of surface at this time of year?