People keep talking about Sisko fighting the Dominion War, but keep forgetting that Sisko proved pretty adept even before the outbreak of formal hostilities.
Remember that Sisko is the one that develops the plan against the Circle when the Federation was ousted by the Bajoran's early on...and exposed the Cardassians involvement in coup attempt on Bajor.
Sisko also developed the plan that saved the Cardassian Detapa Council from being overthrown by the Klingons.
He was absolutely ruthless in dealing with the Maqis and forced Eddington's surrender (by posioning a planet no less).
His actions uncovered Domnion sabetours in high positions in both the Federation and Klingon Empire.
It was his strategy that led to the orderly withdral of the Federation from Bajoran Space and while simultaneously trapping the Domnion in the Alpha quadrant, sabotaging the station (and preventing Bajor from being occupied by the Dominion).
He also devised and led the raid into Dominion/Cardassian territory that destroyed the Dominion's central ketracel white production and distribution center.
On a smaller scale he used pretty significant tactics in ending the Bell Riots without significant bloodshed
I think what ultimately worked in Sisko's favor (from a creative perspecive) is that he faced fairly competent, effective and utterly ruthless adversaries. This forced Sisko to up his game at every turn. More importantly, unlike Kirk, Picard or Janeway, Sisko had the deal with the reprocussions of his actions. Thus even his short term successes could have disastrous long term results or temporary setback could lead to victory. In a way, saving the Detapa council led directly to the Dominion invasion.