Saturday 14 November 2015 09:19, UK
Two-times runners-up Clermont are favourites to claim top spot but Exeter and Ospreys won't make life easy for them, while Bordeaux drew at the Stade Marcel Michelin in September.
Teams: Clermont Auvergne, Ospreys, Exeter Chiefs, Bordeaux-Begles
Champions Cup record: P85 W52 D1 L32
Best finish: Runners-up (2013, 2015)
What's hot: Clermont's squad is jam-packed with international stars and although the Stade Marcel Michelin is not the fortress it once was, it remains an intimidating stadium for visiting teams.
What's not: Clermont have been one of the leading forces in Europe for a number of years but have only one Top 14 title to show for their efforts. Defeats in both domestic and Champions Cup finals last season means the tag of 'chokers' continues to follow Les Jaunards around.
What's changed: David Strettle has made a bright start to his Clermont career with Scott Spedding and Hosea Gear also arriving in the summer to replace the likes of Zac Guildford and Napolioni Nalaga, who has joined Lyon along with veteran Julien Bonnaire.
Key player: Morgan Parra
Champions Cup record: P75 W32 D5 L38
Best finish: Quarter-finals (three times)
What's hot: The majority of their World Cup contingent have returned unscathed and the likes of Dan Biggar and Alun Wyn Jones are in great form.
What's not: The Ospreys have endured a rotten start to the season and sit eighth in the PRO12 after losing five of their first seven games. Their European record is also poor, having failed to reach the knockout stages since 2010.
What's changed: Wales prop Paul James has returned from Bath while former All Blacks scrum-half Brendon Leonard has also moved to the Liberty Stadium.
Key player: Dan Biggar
Champions Cup record: P12 W4 D0 L8
Best finish: Pool stages
What's hot: The Chiefs possess some of the young talent in English rugby, such as Henry Slade and Jack Nowell, and have started the season strongly.
What's not: Exeter are now ranked as one of the top Premiership clubs but they have yet to make the breakthrough into the top four, and their record in Europe isn't good. They cannot afford any injuries to their experienced players.
What's changed: Leicester duo Geoff Parling and Julian Salvi have moved to Sandy Park, which cushions the blow of losing Wallabies lock Dean Mumm.
Key player: Henry Slade
Champions Cup record: P8 W3 D1 L4
Best finish: Pool stages
What's hot: Bordeaux are a tough nut to crack at the Stade Chaban-Delmas and have quality place-kickers in Baptiste Serin and Pierre Bernard.
What's not: With tries hard to come by this season, Les Girondins has been overly reliant on their kickers. Tries are a must if they are to make an impression in their first appearance in the Champions Cup since 1999.
What's changed: Some of Bordeaux's big-name summer signings include Wallabies duo Adam Ashley-Cooper and Sekope Kepu, and former Clermont full-back Jean-Marcellin Buttin.
Key player: Adam Ashley-Cooper
