When Rafael Nadal had his career year in 2010, winning three majors and thereby completing his career Grand Slam, what stood out most was his dramatically improved serve. Suddenly Nadal was serving 130 mph bombs and became nearly unbreakable. It was a huge shift in his game and, as was nearly the case for six months that year, he was nearly unbeatable.
But in one of the bigger mysteries in recent years, Nadal’s serve hasn’t been the same since that U.S. Open. He has reverted back to serving the way he always had – delivering medium-paced and occasionally effective first serves and much weaker second deliveries. While not a total liability, it is decidedly not a weapon most of the time either.