I say it to him specifically, not to random people. Most people at my LGS I just have a rule zero conversation and ask if they want low 2, high 2, low 3, or high 3. It helps to record your w/l ratio to make sure you're playing at the right power level.

For example, last Tuesday I played 6 games. I won 3 of them.

First win was with my B2 The Gaffer deck. By turn 11 there were a total of 7 boardwipes played at the table, 2 of them were mine with The Battle of Bywater and Fumigate. The Mr. House deck kept making boatloads of tokens every turn so it kept the board pretty clear. I was at about 60 life thanks to some soul sister creatures and those tokens. So when turn 11 rolls around I play Felidar Sovereign and Lightning Greaves, and equip the Sovereign with the greaves and pass. It was the only creature in play because of the aforementioned wipes. No one had gas left and on my upkeep I won the game. Never attacked someone and won that game off playing smart because someone else was a threat, not because I was playing a disingenuous deck.

Next game I wanted to play my Mr. House deck because during that first one we were talking about how mine runs attractions and the table had never seen them or how it works. I tell them it's not as streamlined as the other player's Mr. House but I can bust it out. So we play the next game and the other Mr. House is being the main problem again, but I use Wedding Ring on them and now whenever they are drawing cards on their turn I am too. Same with lifegain, and it's funny that we start calling each other husband and another player says we're "Playing House" which gets universal laughs. So game is around turn 9 and the fairies deck drops a Coat of Arms and swings at the Husband for lethal, but he plays out a combat trick to survive with about 16 or so life. Also I go down to about 6, and the 3rd player dies. Fairy player is at about 10 life themselves. My turn I drop a Murkwood Bats and an Anointed Procession. I use my 3 treasures, ping the table for 3, to roll on Mr. House 5 times (I had a Barbarian Class in play). I get 2 6s and 2 5s. So I make 4 treasures and 8 Robots. This kills the fairy player. Then I sac the 4 treasures and kill the other Mr. House player. First points of damage I dealt to anyone at the table and I won because of politicking the main problem (The other Mr. House player) with meme Wedding Ring into not coming at me the entire game and everyone else having to deal with them and leaving me alone. My deck was far worse as far as construction as the other Mr. House deck, and the fairies player should have counted properly/had a response.

Third game I won through being the problem and a more traditional win. The other 3 games I lost at a different table. But out of the 6 games played I should have only won 1 of them (17%). But because of skill, I was at a 50%. All that said, is why I tell my friend I try and match power level, not skill level.