Tour Championship: Paul Casey takes a share of halfway lead as Spieth falters
|Tour Championship second-round leaderboard|
|-7 P Casey (Eng), J Thomas (US), W Simpson (US); -6 P Reed (US), J Rose (Eng), G Woodland (US), J Rahm (Spa); -5 X Schauffele (US), J Dufner (US)|
England's Paul Casey moved into a share of the lead at halfway in the Tour Championship as FedEx points leader Jordan Spieth fell off the pace.
Casey shot a 67 to move to seven under, alongside Americans Webb Simpson (67) and Justin Thomas (66) in Atlanta.
Thomas is second in the FedEx standings and is one of five who can win the title with victory at East Lake.
World number two Spieth is another of those, but he shot 70 to remain three under for the tournament.
Spain's Jon Rahm, who is fifth in the points list, is one of four on six under after his 67, along with England's Justin Rose (66) and American duo Patrick Reed (65) and Gary Woodland (67).
Rose is eighth on the points list, while compatriot Casey is 10th.
Any of the 30 players in the season-ending event can theoretically win the $10m (£7.4m) prize on offer, but only those in the top five in the standings are assured of doing so by claiming victory in Atlanta.
Open champion Spieth began the tournament with a 200-point lead over Thomas.
World number one Johnson, currently three under, and Australian Marc Leishman, who is two over, are the other players who will win the FedEx Cup with victory in the Tour Championship.