Quarter-final crunch time

However, Harlequins hold a commanding six points lead at the top of Pool 4 and a Round 5 win over Ulster Rugby at Ravenhill would guarantee Quins quarter-final qualification - but not all important ranking with home advantage going to the best four Pool winners.

And Cardiff Blues are in the Pool 6 driving seat, four points clear of Gloucester Rugby with their Kingsholm Sunday showdown potentially the clash of Round 5.

Since the format of the two best runners-up qualifying for the quarter-finals as the No 7 and No 8 ranked teams has been in operation since the 1999 / 2000 season and bonus points coming into the equation in season 2003 / 2004, here are some quarter-final qualification pointers:

• No team has qualified as Pool winners on less than four wins.
• No team has qualified as one of the best runners-up on less than four wins.
• Since bonus points were introduced no team has qualified as a Pool winner on less than 18 points (Stade Français Paris in 2003 / 2004).
• Since bonus points were introduced no team has qualified as one of the best runners-up on less than 19 points (Leicester Tigers in 2004 / 2005)

The maximum points and wins attainable by each team on current standings are:

POOL 1
Munster - 23 points / 5 wins
Sale Sharks - 21 points / 4 wins
ASM Clermont Auvergne - 18 points / 4 wins
Montauban - 16 points / 3 wins

POOL 2
Leinster - 25 points / 5 wins
London Wasps - 22 points / 5 wins
Castres Olympique - 15 points / 3 wins
Edinburgh - 14 points / 3 wins

POOL 3
Ospreys - 25 / 5 wins
Leicester Tigers - 25 points / 5 wins
Perpignan - 19 points / 4 wins
Benetton Treviso - 10 points / 2 wins

POOL 4
Harlequins - 27 points / 6 wins
Stade Français Paris - 21 points / 4 wins
Ulster Rugby - 16 points / 3 wins
Scarlets - 13 points / 2 wins

POOL 5
Toulouse - 27 points / 6 wins
Bath Rugby - 25 points / 5 wins
Newport Gwent Dragons - 15 points / 3 wins
Glasgow Warriors - 14 points / 2 wins

POOL 6
Cardiff Blues - 28 points / 6 wins
Gloucester Rugby - 24 points / 5 wins
Biarritz Olympique - 17 points / 3 wins
Rugby Calvisano - 10 points / 2 wins