Interesting, and there's something in it, but a little simplistic.
The majority of the time will see Mackie subbed on when we are already not in the ascendancy.
Some chicken and egg to consider.
And I am always happy to.
I appreciate the point that it is simplistic (I have a job and some other hobbies after all. Okay, I have a job).
However, allow me to defend the worth of it. There are two main points I'd draw attention to, and any non-geek can look away now.
Firstly, if Mackie is subbed on when we are not winning, then that should mean our goals for/against without Mackie is worse. Teams that are 3-1 up and called Man City don't need to pile in and score more goals (and they didn't). Plus, the team without Mackie has taken a 3-1 hit in the very crude measure I used, which makes his record look better by comparison.
Secondly, I dispute the use of Mackie primarily to come on and change a game. At this point I'll add that I'm not Opta. I've checked these but they should be used for broad ideas rather than as an exact science.
Mackie has played 15 minutes or less (therefore probably bought on as a late sub) 12 times this year (I assumed a game ran for 96 minutes, to acknowledge that a player brought on in the 90th still has time to score). We have not scored in that time during any of these 12 games. Only twice have we been losing (Sunderland home, Peterborough away). In those two games, we scored none and went on to concede one more against Posh, so I would agree with the sentiment that he doesn't change a game, but he isn't asked to very often. He performs well enough in helping close out a game with an appearance in the final minutes but I have nothing to benchmark against.
I have him playing 60 minutes or more 21 times this season. That accounts for 85% of the time he has been on the pitch. In those minutes, our record is scored 28, conceded 24.
In the same games, I have 360 minutes without Mackie on the pitch. In that time, we have impressively scored 15 and conceded 1. This includes West Ham, where we were 1-0 up and went on to win 4-0. It includes Newcastle, where we were 2-0 down (and went on to lose 3-2). Millwall, where we were 2-0 down and drew 2-2. Bristol Rovers, where we were 1-0 up when Taylor got injured in the first half and lost 3-1.
This might support the idea that we are just far better without him on the pitch. But it certainly gives rise to the question of whether Mackie tires out a defence and Taylor/Agyei/anyone else reap the benefits.
But this is a really difficult area to unpick. The key games (for me) were West Ham, Millwall, Newcastle, Lincoln, and Hartlepool, which together account for 11-1 of the 15-1 differential. I think at this point, it's best for each individual to rely on what they saw with their eyes and gauge how much we benefited from these teams being tired out from having to deal with him for over an hour.
For me, the answer is - not much. We were chasing Newcastle and Millwall and had to attack. Three of the teams highlighted are in higher leagues, and really shouldn't be tired out by any lower league player.
If the plan is to use Mackie to tire out a team and take advantage in the closing minutes, that would only make sense to me in games where we can be sure of drawing by the time he comes off. Accepting a losing position on the basis we can turn it round at the end would be absurd. The only 60+ minute appearances I have us drawing when Mackie comes off are Accrington and Gills away. In both games, we failed to win.
In the games where Mackie plays less than 60 minutes, we have scored 36 and conceded 21 without him on the pitch. I think we are a very good team when we have a striker that can score goals, and should not take the risk of overthinking our game plan.
