Hey guys, so I use Whoscored.com.
They do a rating system that's far from perfect, but it's a nice consistent view so I went that way a couple of years back and have stuck with it.
Here are the pages for the recent games as an example, showing the ratings and the MOM's;
https://www.whoscored.com/Matches/1549819/Live/England-Premier-League-2021-2022-Arsenal-Leicester
https://www.whoscored.com/Matches/1549822/Live/England-Premier-League-2021-2022-Chelsea-Newcastle-United
https://www.whoscored.com/Matches/1549821/Live/England-Premier-League-2021-2022-Brighton-Liverpool
For the record I would've picked Odegaard as MOM too, but Partey did have a good game. Goals/assists, clean sheets, personal errors, all seem to carry a lot of weight in their rating system.
Also, sometimes more than one player will have the same rating, and Whoscored will mark one of them as MOM above the others, but I ignore that - anyone with that highest rating score, I give as equal MOM, and award points for anyone picking any of the players with that highest rating. For example in a recent game there were three Arsenal players with equal highest, so scored full marks for anyone picking any of the three.