With bike racing, don't think in percentages. "Top half" etc. It's basically "in the money" or not. Top 3 (podium, even if it's just imaginary), top 6 or so (points for upgrades on your license, more places for certain qualifying race traits, less for others). Everyone else is The Pack, i.e. "I finished in the pack" or "I was off the back".
Some races won't score/publicize more than the places - 3 or 10 or whatever places. You got 11th? You may not get listed. It's actually unimportant in the scheme of race results other than showing you finished or not.
Bike racing is much less a measure of strength/fitness and much more a measure of tactical skill. This isn't true for time trials or climbing longish hills but, importantly, time trials don't count towards upgrades. Why? Because you can be brain dead and ride a really good time trial. You can be an absolute menace to the safety of others in a pack and still ride a time trial really, really fast. In fact I'm going to meet with someone who is petrified of riding in a group but does 27-28 mph time trials (and runs about a 5:30 minute pace for 5-10k races - she won the overall at a local-to-her race a few weeks ago). She's a friend of the family and is thinking about getting into bike racing.
For a long time road races counted for more points than crits. Road races require both tactical sense and fitness. Crits tend to measure tactical sense more than anything else.
Fitness-wise I'm probably a Cat 5 in a road race, Cat 4 or 5 in a time trial, but I'm a reasonable Cat 3 in a crit. Remember that in crits fitness is not the end all, it's tactics. One of my hardest races in 2010 was one where I averaged 179 watts for about 40 minutes. Kind of a joke right? But that was a Cat 3 race, a hotly contested one too, one of the big crits in the summer.
The reason bike racing is addictive to some (like me) and not to others is that tactically you can always improve. Although fitness gives you more tactical options, you can be unfit and do well. I raced against a guy whose belly literally hung on his top tube. It swayed back and forth when he was out of the saddle. I thought it was an absolute disgrace that this guy was in the same race as me, a Cat 3 or Cat 3-4 race.
But you know what? The short-ish quarter ton rider won the race. He demolished the field in the sprint. He rode a smart race and used his "former professional bronze medal in the Keirin" legs to propel all that extra fat and stuff across the line probably 50 feet in front of the next guy. He's an extremely astute tactician and used his brain to beat everyone else.
If he can do it, so can I. I won a field sprint at almost 200 lbs on an uphill finish in a Cat 3-4 race. My belly probably swayed too - I ride a size S Giant or a 52 Cannondale, and I'm 5'7". If I can do that, I can try to do as well at a lighter weight, with a much lighter bike, etc etc etc. So I come back and try to do better with whatever I have. It's frustratingly addictive.
cdr