I'm completely confused about my rating.

I'm english so my main rating is the ECF grading system. When I came on to chess.com I guessed that my true strength was about 120 (ECF) which predicts that my raating would settle about 1800 (chess.com), which it did.

Then I see a load of posts saying that chess.com ratings are overrated which suggests that I overestimated my strength, but yesterday I took out two 165 (ECF) strength players without any trouble which suggests I've massively underrated my strength.

I'm confused!

Look at it this way:

Online ratings and OTB ratings have a lot less correlation than some people believe. Some people will be overrated, but some will be underrated. This comes about because with such large time controls, some people move very quickly (as though they were playing G/30 OTB) whereas some take hours to analyse positions.

1) comparing ratings from two different pools of players, under different rules probably means that they are just too different to make a valid comparision (e.g I'm 130 ECF but 2100 here.)

2) you beat two players, that isn't really enough games for any conclusion to be statisically significant.  

just play more and more games, and your numbers should get more and more accurate. 

OTB and correspondence chess are very different skills....

OG

Also, I've heard that USCF ratings, which use the same number scale as chess.com, are usually about 200-300 points lower than your online rating.

BCF stands for British Chess Federation, which has recently become ECF, English Chess Federation, as the Welsh, Scottish and Irish now have their own.

OG

It's really not fair to compare ratings from one place to another. To borrow an example from soccer (football to most of the world). If a player boasts that they were able to score 15 goals in a season in the Scottish Premiere league, does that mean that they will be able to score 35 if they had played the same season in the English Permiere league? Not necessarily. The two leagues are completely different, have different players, and have no direct corrlelation. The same goes with chess "leagues" or organizations, there's no direct correlation between them, so they really can't be compared.

One thing to keep in mind is that your rating is by nature relative. It is not a measure of your skill, instead it combines with your opponent's rating to estimate the result of the game. It only has meaning relative to other people, specifically other people in the same rating pool.

My most popular blog entry ever (over 10,000 reads) is Elo to Glicko: Your Rating Explained

 ....having sat through the dross that is Scottish football for decades, there is no danger that a good SPL striker could bag themselves the same or more goals down the road :)

Rich, you never have had any USCF, FIDE or ECF (it's ECF) rating. God, I really hate you. I mean what kind of sad pleasure could anyone get out of lying about this stuff?

The British Chess Federation ceased to exist more than 2 years ago.

Also:

http://grading.bcfservices.org.uk/getplayers.php?players=mccarthy

....nope, no mention of any Richard McCarthy.

So that's yet ANOTHER porkie you've told everyone. If you are going to lie at least make sure they are good ones, not something that anyone can look up in a few seconds.

So to summarise,

you are an Englishman who chooses not to use the ECF but instead prefers some long since defunct organisation and your grading of 75 is also fictitious. By extrapolation one might also infer that since you have no ECF grading, the stories you tell of OTB tournaments are also lies. Tell me rich, does a word of truth EVER pass your lips?  

I suggest you quit this charade now.