Simple: Ownership. It starts from the top. Ownership sets the tone, the culture and strategic goals, signs off on big moves, hires the front office who in turn make the strategic decisions on running a franchise, hiring a coach, building a team of players, etc.
If you want proof, just look at cases of perennial losing and winning franchises across different sports.
- Los Angeles Clippers under Donald Sterling
- Golden State Warriors under Chris Cohan
- New York Knicks under James Dolan
- Detroit Lions under the Fords
- Washington Redskins under Daniel Snyder
- New England Patriots under Robert Kraft
- San Antonio Spurs under Peter Holt
- Los Angeles Lakers under the late Jerry Buss
- Golden State Warriors under Joe Lacob
A great example of the difference an owner can make is the Warriors. Long time owner Chris Cohan oversaw decades of being a bottom dweller laughing stock team, dysfunction and turmoil in the front office, a culture more worried about entertainment than winning, etc. So what happened? He made decisions based on his goals, and his incompetence permeated throughout the franchise. They didn't care about winning, they made horrible trades, drafts, decisions, etc. Now comes along Joe Lacob, who transformed the entire franchise: created a winning culture, hired competent/respected/smart front office, made great decisions with drafts, trades, free agency, etc. The Warriors went from absolute laughing stock, to powerhouse dynasty, in less than 5 yrs of new ownership. Good, bad, or mediocre, this happens all across sports.