I can’t believe I’m giving social advice on HN, but maybe it will help.

> I told him what I did and he didn't take it well

This was a mistake. Ask yourself why you did it. If you don’t have a good answer, one possibility is that it was your ego. Another is your very strong adherence to a certain code of behavior that others do not relate to.

> we'd both keep striving to improve and competing with each other

I’m not sure competing with someone who is not on your level is a normal approach.

I also doubt your friend sees the situation the same way as you. They are more of a recreational player. It’s a level below where you are, but for some reason you want them to care more.

> I'll lose 90% of the time if I do online matchmaking

And yet playing in person is important to you. It’s fun?

> it's not very fun letting people win, and it feels dishonest and disrespectful as well

At work, you want people on your team to pull their weight even though you could do the job better. How do you keep them from being discouraged? A strategy like this works.