LONDON. Serena Williams heads to Wimbledon to defend her title with seeds of doubt and defeatism already sown in the minds of her opponents.The psychological scars of playing the younger Williams sister run deep in the women’s game and, now that the American has dusted off the red clay from her shoes, predictions of an upset on southwest London’s luscious lawns are few and far between.Having bludgeoned her way to a 16th grand slam and second title at Roland Garros, Williams can now tighten her grip still further on the sport she has come to dominate by claiming a fourth major in five attempts.It is little wonder then that Williams’s rivals for the Wimbledon title can realistically be counted on one hand.Her opponent in the final at Roland Garros, Maria Sharapova, and Belarussian world number two Victoria Azarenka are the leading candidates to throw a spanner in the works.Confidence, however, is hardly overflowing. Sharapova was circumspect to say the least on entering the French Open final having lost 12 consecutive matches to Williams."I’d be lying if I said it doesn’t bother me, obviously,” the Russian said of a losing record stretching back to 2004.Defeat in the quarter-finals of the Australian Open in January is the only smudge on a near-perfect year in which Williams has returned to the pinnacle of the rankings and re-conquered Paris, where the title had eluded her since 2002.She is on a 31-match winning streak with a 75-4 win-loss record in the past 12 months and has the added comfort of knowing that her game is ideally suited to the All England Club where her huge serve and heavy hits skid through with a little extra fizz.Petra Kvitova, 2011 Wimbledon champion, is not the first to suggest that Serena’s biggest opponent is frequently herself."I think that the players have to play 100 percent and to play really, really well. Serena sometimes doesn’t have a great day but she’s still able to beat the other players,” she told Reuters.World number five Sara Errani, who was on the receiving end of one of Williams’s most emphatic maulings in the semi-finals in Paris, losing 6-0 6-1, neatly summed up the sense of foreboding.