I've said this before and I say it again. The reason Delph is showing how good he is, is in my opinion because if his no fear mentality. He doesn't show any respect in the field and works his socks of every minute he spend on the pitch.
Delph also have the courage (sometimes stupidity) to take people on no matter what. If he fails he then don't moan about loosing the ball. No, Delph works his ass off to get the ball back. This mentality is captaincy mentality. Such work rates and display give the team members confidence and make them work harder aswell.
Long story short, Delph has been phenomenal and if he manages to avoid injuries he will be the player of the season for us!