. d 4 , ▁ 5 . N xf 7 , ▁or ▁ 5 . B xf 7 + . ▁After ▁ 5 . d 4 ▁d 5 !, ▁White ' s ▁best ▁is ▁to ▁go ▁into ▁an ▁equal ▁end game ▁after ▁ 6 . dx c 5 ▁dx c 4 ▁ 7 . Q x d 8 + . ▁Other ▁sixth ▁moves ▁have ▁scored ▁very ▁badly ▁for ▁White . ▁▁ 5 . N xf 7 ▁is ▁very ▁complicated ▁after ▁ 5 ... B xf 2 + . ▁The ▁current ▁main ▁lines ▁all ▁are ▁thought ▁to ▁lead ▁to ▁drawn ▁or ▁equal ▁positions , ▁e . g . ▁after ▁ 6 . K xf 2 ▁N xe 4 + ▁ 7 . K g 1 , ▁or ▁even ▁ 7 . Ke 3 . ▁ ▁White ' s ▁best ▁try ▁for ▁an ▁advantage ▁is ▁probably ▁ 5 . B xf 7 + ▁Ke 7 ▁ 6 . B b 3 ▁( although ▁ 6 . B d 5 ▁was ▁the ▁move ▁recommended ▁by ▁Lawrence ▁Tr ent ▁in ▁his ▁recent ▁F rit zt ra iner ▁DVD ), ▁as ▁this ▁pos es ▁Black ▁the ▁most ▁problems . ▁No ▁grand master s ▁have ▁regularly ▁adopted ▁the ▁Wil kes - Bar re ▁as ▁Black , ▁but ▁Alexander ▁Bel ia v sky ▁and ▁Alex ei ▁Sh iro v ▁have ▁played ▁it ▁occasionally ▁even ▁in ▁top ▁competition . ▁No ▁clear ▁ref ut ation ▁is ▁known . ▁▁ 4 ... N xe 4 ▁ 4 ... N xe 4 ? !