The phrase "winnable match" means a game or competition that is highly likely to be won by someone, because the person or team has a good chance of being successful in it. Full definition
It's back to home soil for them this weekend where they have winnable match on their hands against the league's worst away side. (football-bookmakers.com)
Tough home match will be gainst Chelsea, so I assume rest all are winnable matches even with this squad. (justarsenal.com)
Including this one there are manageable and even winnable matches still to come for Stoke, but getting them is going to be a different matter entirely. (football-bookmakers.com)