In 2007 MS Dhoni won the first T20 World Cup. In 2014 he won the last T20 Champions League. In between he won everything. But since then Dhoni is really struggling to win series and tournaments as wins are much rarer.
He's not doing well as captain of RPS either having lost four straight matches on the trot, an unprecedented feat for him in IPL. He has lost to captains Suresh Raina, Gautam Gambhir and Virat Kohli. To make matters worse, his star batsman Kevin Pietersen has been ruled out of the tournament due to an injury.
From here on it's quite a tough task for Dhoni, even though he is known to pull of anything at the last moment. Raina on the other hand is doing wonders for Gujarat Lions, having won 4 of his first 5 matches and he's on course to become the first player to score 4000 IPL runs.