Shard O'Glase said:at 10th level a rogue should only be missing 15% more often than the fighter. considering that the rogue will likely be doing more than 15% more damage per hit this balances out fairly nicely for damage, which it shouldn't IMO.
Sorry, but you should be looking at the ratio of the number of hits, not the difference in the hit percentage.
Consider if the fighter needs a 11 to hit with their first attack. They will hit 50% of the time on their first attack and 25% on their second. If the rogue requires three more, that would be a 14 which means they hit 35% and 10% of the time.
In this case, the fighter is hitting 15 times for every 9 hits by the rogue (almost a 2 to 1 ratio) and also has a much better chance of confirming criticals. The rogue can get lucky and do significant damage, but the fighter is the one that will consistently dish out damage.
After 10th level, the gap becomes wider as the fighter gets their 3rd atttack at 11th level and 4th attack at 15th. The rogue gets their third attack at 15th -- the same time as the fighter gets their fourth. An extra attack makes a huge difference in how much damage a character can pump out. If the fighter is specializing in a weapon, they are probably picking up Improved Critical and (with 3.5) the Greater Weapon Focus/Specialization as well.
Every trick that the rogue plays to improve their to-hit, the fighter can match or better. In every group I've been in, the fighter gets first pick of weapons and therefore is likely to widen the gap further.
How often the rogue will hit compared to the fighter will also depend heavily on what the AC of creatures you are fighting is. When it gets to the point where the rogue is only hitting on a natural 20, the fighter is hitting four times for every hit by the rogue.
I haven't had time to run a Rogue/Fighter up to high levels. The one dwarven Ro/Fi I was running had the campaign fold much too early. From what I can tell, taking just 4 levels of Fighter can make a significant difference for the rogue -- three more feats, allowed to specialize in a weapon, better weapon selection, and will have a higher BAB which gets you to multiple attacks sooner. This would tilt the results.