 In 2007 , <unk> <unk> Georgiev and <unk> Kolev asserted that much the same was true of the so @-@ called <unk> <unk> Variation of the <unk> Sicilian , which arises after 1.e4 c5 2.Nf3 d6 <unk> cxd4 <unk> Nf6 <unk> a6 6.Bg5 e6 <unk> <unk> ! ? This has long been considered one of the <unk> and most problematic , or even <unk> , opening lines . The game usually continues <unk> <unk> <unk> <unk> . Georgiev and Kolev stated that 6.Bg5 is seldom seen at the highest level because the main line of this variation leads , with best play , to a draw by perpetual check . They wrote that the following game " will probably remain the last word of theory " : 
