What’s our record been with him in the team this year? Although I don’t think he’s done great in terms of direct goal involvements, I do think he’s very very good in terms of creating space for others and they’ve capitalised on it most times he’s played.
This is going to be a long one, feel free to ignore if you're not into stats. Disclaimer, I'm just quickly adding them up off transfrmarkt so apologies if I'm slightly off anywhere.
I'm including matches where he came off the bench as him playing, just for ease of the maths.
And I've taken the details for Premier League, Champions League and FA Cup only.
So across those 3 major competitions in the 33 matches he's appeared in, we've won 23, drew 5, lost 5, scored 82, conceded 27.
And in the same competitions in the 17 matches he hasn't appeared in, we've won 14, lost 1, drew 2, scored 43, conceded 13.
So with him, we win 2.24 points per game, scoring 2.49 goals and conceding 0.82.
And without him, we win 2.59 points per game, scoring 2.53 goals and conceding 0.76.
So the headline is we've been slightly worse with him than without him, but it's actually very close. We can probably make arguments either way about the quality of opponents faced and not faced, the strength of the rest of the line up, and to what extent Jack or the person playing in his place influenced each match.
But the raw numbers say we've been a little worse with him, but either way on average we win by over 1.5 goals. I'd argue that's pretty good going for a player who's joined one of the best teams in the world, with a style of play it famously takes a long time to adapt to, when he's by his own admission felt he's struggled a bit this year.
Out of interest, I compared these figures with the first season of Mahrez, a player Grealish has tended to be compared unfavourably with in this thread. Same rules - any appearance counts as a match played, and I'm looking at the same 3 competitions.
Total played: 38. Won 30, drew 3, lost 5, scored 108, conceded 26.
Total not played: 16. Won 15, lost 1, scored 41, conceded 11.
With him per game: 2.45 points, scored 2.84, conceded 0.68
Without him per game: 2.81 points, scored 2.56, conceded 0.69.
As near as makes no difference, it's the same sort of comparable difference as Grealish has. Yeah, we scored more goals with Mahrez than without him, but still we were winning more points without him (and generally back then we were scoring a little more, winning our matches by more like 2 goals).