One of WrestleMania's greatest strengths is its status as a culmination point. It's the natural end of the WWE's calendar, a place where storylines reach their conclusion, often providing fantastic moments of satisfaction and closure. One only needs to look at Daniel Bryan's triumph last year to see the success of this simple formula. The diminutive challenger was the fans' unanimous favourite; everybody including the WWE knew a victory for Bryan was the best possible outcome - therefore it happened. Sometimes the obvious nature of an ending doesn't strip away its power, a motto WrestleMania has often thrived under. The relative predictability of 'Mania compared to other PPVs therefore leaves the door open for a bigger upsets. Unexpected results ring with particular resonance at the Showcase of the Immortals, not only due to the heightened sense of scale, but also the fact that they often fly in the face of an especially certain outcome. Wrestlemania upsets typically provoke extreme reactions - for better or for worse. Some shocks can be regarded as masterstrokes, high-risk booking decisions executed well on the grandest stage of all. Others are a sign of unwise, rushed, or simply lazy booking. Their consequences are naturally far-reaching as a result of WrestleMania's influence, often resulting in fierce debate and strong reactions for many months. They can provide a springboard for an upcoming worker or kill their credibility in a few moments; just imagine the crowd's mutiny if Batista or Orton had stopped Bryan's charge to the title last year. Despite the mixed results an upset can provide, their powerful sense of initial shock remains undiminished after three decades. Upsets are part of the fabric of WrestleMania, albeit a sometimes unwelcome one. Here are ten of the biggest upsets WrestleMania has seen in its spectacular 30 year history. Be sure to add your favourites in the comments section below.