It's not errors -- for instance, today I scored a 48 Q on a practice test with 15 wrong. Because it's a CAT, it's expected (and normal) that you get several answers wrong - they get harder each one you get right! Someone with a 600 score and someone with a 700 score could each get the same number of questions wrong, it's just that the person with the 700 got harder questions wrong than the person with the 600 score.

Hope that helps!

Oh I see. So it sounds like someone who gets 51 may have some errors.

^^ yes, even if you score 51, you are allowed to have some errors. It the level of the question, i.e. its difficulty that decides

In fact all of my 700+ practice scores had more errors than my 620-640 scores. The key is to try get to th difficult questions coz if you get a 750 level question worng all the computer will do is give you a 740 level one, and if you get that one wrong, you get a 730 level . Whereas getting 630 wrong gets you lower. So you don't want to get easy questions wrong, but you shouldn't worry too much about getting hard questions wrong.

However, on the very high levels of verbal, getting 3 wrong as opposed to 1 can have a HUGE effect e.g. you might get 49 for 1 wrong and 43 for 3 wrong.

I agree that the amount of wrong questions has a bigger impact on your score on V than on Q but I don't know if the above is a hard and fast rule. On one of my practice tests, I got 5 wrong and got a 45. On another I got 9 wrong and got a 44. On still another, I got 10 wrong and got a 45.

The GMAT has an annoyingly complex scoring system is the conclusion I think we should reach.

I was just giving an example. I didn't mean to imply that 1 wrong = 49 everytime.