Bob,
Actually, I keep an excel spreadsheet of my scores in the various classes, so I have a pretty good idea how I'm doing compared to last year, which is most important to me.
Last year, I finished in 7th in Open Overall last year, but there are guys ranked this year who weren't last year, like Don Howard and Lee Liddle, and some of the guys from last year have obviously stepped it up a notch. Locally (where I do most of my flying, after all), several guys have picked it up a notch from last year as well, so that means less streamers left late in rounds, and a harder time getting the "big round" posted.
Last year, my average was a 415 for my top 20 open rounds. I struggled a lot in B last year, but I'm doing better there this year. I'm hoping to finish the year with a 450 average for my top 20 rounds. I can do that with out the 600+ point rounds, but it will be hard. Last year, I had 1 700pt round and nothing in the 600 range. So, you're right, I could use a few 700+ pointers. But they are hard to get, espeically since the vast majority of heats I fly in have 5-6 planes (including mine) in them. I think Nats will be the last contest for me this year where I can expect to see 8+ planes in the air.
Standings wise, I figure a 450 will be around 8th-12th place at the end of the year. So, I expect to finish with a higher point average, but lower standing than last year.
Oh, if you were watching me at Dixie, you saw a prime example of how "streaky" I can be. My B scores were:
160 20 240 540 -400 480 400 240
Clearly, I started the contest with two "futility" rounds where I couldn't get anywhere near a streamer. Then I got my brain in gear and things clicked for me in round 4. (the -400 was traced back to a loose crystal a little while after the contest. Stooopid! Boot to the head for endangering folks with badly preped gear.)
The funny thing is that I am too inconsistant to be a threat to win a "major" contest. I've never been able to keep it together for 8+ rounds at once. Everyone has a low score round here and there, but I get too many of them. But I get enough high rounds that by the end of the season I should have enough high point rounds to get my average up there.
(btw, I'm a computer programer and database guy with a serious streak of "number geek" so I can spend a lot of time playing with NPS scores and the like. But it's all for fun, I really don't take it that seriously)
Anyway, here's a way to look at NPS. After NE Nats gets posted, my low score in the overall Open categegory will be a 220. That means any round below that "doesn't count", and if I post a 540, my NPS score will go up by 320 points. I have 8 of my 20 rounds currently under 300pts. So every time I score 400+, I go up in points a noticeable amount. But, and here's the kicker, if I get hot at Nats, my upwards progress will slow way way down for the rest of the season, as I start to do things like replace a 260 with a 340 for example.
Oh, and after NE Nats is posted, I'll move up just under 200pts, to 7236. Not enough to jump a spot, but close.
I just dropped your son's scores in to a spreadsheet, and I see that he's in pretty good position right now. After NE Nats, he'll be about 700pts behind me, but you have a number of low score rounds that will drop off, raising your score quickly at first. A single 900pt round will put him above me, as I think the low score is a 170something.
There are really two keys to doing well in NPS.
First, the more rounds you fly, the more high point rounds you pick up. It's possible to get high in NPS by being "streaky" and posting the high round here and there while never coming close to winning a contest. Last year, less than 1 round in 10 for me was over 400pts. But I managed 7th, go figure. (so far this year, 1 round in 4 is 400pts or higher (open classes only), a good sign for me)
Second, you have to fly enough rounds with enough targets available to get those 7+ cut rounds. One round in that area can really make a huge difference. Ben (whom I think is a better pilot than me) has a 900+pt round. If you take that away and replace it with a 500+ pt round, he goes down 400 NPS points and drops from 4th to 6th. That's a big impact from one round out of 60-80 most of the top NPS scorers flew last year.
Anyway, NPS is fun, but not a perfect measure of pilot skill, that's for sure. BUT, and this is key, I don't think it needs to be changed or should be changed. It's fine the way it is. RCCA went though a huge mess getting it the way it is, there is no reason, IMHO to go though it again.
So, after all that, how am I doing this year? Well, I'm still streaky as all get out. I still have equipment problems that come from lack of enough preparation, and I have a few key design problems with some of my planes that I need to work out. I figure if I get my stuff all together, I can really be dangerous in 2004.

We'll see.