Minky usually suggests to have all ten people there, if I recall correctly.
In DotA2, on the results screen you have the option to up- or downvote each player, and they see it. I find the single upvote a little restrictive, and it usually results in a funky outcome: everyone with one vote, sometimes except the MVP who has none (got from the game, or played a stomp hero, or one that requires babysitting). Occasionally there are people with multiple upvotes, if they were really stellar.
Fairly often there are barely any votes, after bad, one sided matches. In fact it’s kind of a sellout for analysis.