As you well know, ELO Boost is a practice penalized by Riot; for this reason, people who buy ELO Boost are cautious when it comes to securing their account.
They are usually intelligent people, they know this penalty, and therefore they usually buy it rather gradually.
It is very rare to see a purchase of elo boost superior to a full league, although it might be the case.
However, it is also true that it may be the case that he is no longer playing with desire or that he loses the same as losing and just hanging out. For this reason, it is not very easy to identify them.
When we play league of legends and have a bad game, who has not happened that, being platinum up, they are called ELO boosted for perhaps not making a rotation properly?
It is impossible to determine if a person is eloboosted by a simple bad game, this is important to take into account and correct our behaviour when speaking to this player.
In case you see a sudden rise in ELO within that graph, then you might think that it is indeed an eloboosted person.
But be careful, We would still need more evidence to be able to report him properly since that person could have suddenly improved and managed to climb leagues very quickly.
An elo boost which you can find at https://elo-boosters.com/ could be the same, but in a week, it is also possible that players can make such a big improvement if they practice enough with another smurf account.
To verify that it is an elo boost, we must provide evidence on in-game attitude.
If it turns out to be a player with a negative tendency (pulling toxic), with a low level of play in multiple games, we increase the probability of being an elo boost player.
We should record the games and bring the replays to Riot where it is clear that the player does not have the level of the league multiple times.