Defeat for West Ham against Chelsea could see them sucked into the relegation zone. Opta have all the vital statistics.
"No side have won fewer points at home in the Premier League than West Ham (4) this season (W1 D1 L3)."
West Ham are without a win in four Barclays Premier League home games (L3 D1); their worst such run under Sam Allardyce. Chelsea are 1.635/8 to win.
Chelsea are unbeaten in their last six Barclays Premier League London derbies (W4 D2). The draw is 4.216/5.
Frank Lampard has scored in three of his last four Premier League appearances against former side West Ham. Lampard is 3.259/4 to score.
However, Frank Lampard has failed to score in 10 successive Premier League apps - his longest goal drought in the competition since April-August 2003. West Ham are 6.411/2 to keep a clean sheet.
Against no side has Fernando Torres netted more Premier League goals than he has versus West Ham United (six goals in seven games). Torres is 2.56/4 to score.
No side have won fewer points at home in the Premier League than West Ham (4) this season (W1 D1 L3). Chelsea are 2.526/4 to win half-time/full-time.
All 12 of Jose Mourinho's Premier League defeats as a manager have come away from home, but just two of these have come in London (v Fulham in March 2006 and Tottenham in November 2006). West Ham are 6.411/2 to win.
However, of all managers in Premier League history (minimum 15 games), Mourinho has the best points per game record away from home (2.05). Chelsea are 2.526/4 to win to nil.
Sam Allardyce has picked up just two points in his previous six Premier League meetings with Jose Mourinho (D2 L4), but he's lost all three of his home games against him. Chelsea are 4.03/1 to win to nil.