switz, you and I have covered some of these same points before.
What is it with people who think an RB needs 20 carries a game to be good?
I agree with this point. However, I do think a RB needs to average 15+ carries to be good, or in this case, to get a true opportunity to be good. To average 15+ carries per game, a RB will need to have a number of games of 20 carries or more to offset games with fewer carries. Barlow has had only one game (before today) in his career with more than 15 carries, and he has averaged less than 10 carries per game for his career. IMO he has not been given a true opportunity to prove himself, and thus cannot be judged to have failed.
Does LT average 20 carries a game? No.
As a matter of fact, LT has averaged 21+ carries per game in his career (before today), so you chose a bad example to back your point.
Barlow has had 6 games witth 15-18 carries. He's averaged 67.5 yards per game, at 4.3 YPC, not bad, not spectacular
Since you chose to use LT in your earlier argument, I decided to compare his games with 18 or fewer carries to Barlow's, just to get as close to an apples to apples comparison as possible. Here are LT's games with 18 carries or less:
2001
+----------+-------------+----+
| WK OPP | RSH YD | TD |
+----------+-------------+----+
| 7 buf | 16 76 | 0 |
| 8 kan | 13 31 | 1 |
| 9 den | 14 75 | 0 |
| 14 oak | 17 46 | 0 |
| 16 sea | 14 38 | 0 |
+----------+-------------+----+
| TOTAL | 74 266 | 1 |
+----------+-------------+----+
2002
+----------+-------------+----+
| WK OPP | RSH YD | TD |
+----------+-------------+----+
| 5 den | 14 48 | 0 |
| 9 nyj | 12 60 | 1 |
| 12 mia | 14 45 | 0 |
| 14 oak | 18 57 | 1 |
| 17 sea | 17 67 | 0 |
+----------+-------------+----+
| TOTAL | 75 277 | 2 |
+----------+-------------+----+
2003
+----------+-------------+----+
| WK OPP | RSH YD | TD |
+----------+-------------+----+
| 1 kan | 13 34 | 0 |
| 2 den | 16 93 | 0 |
| 5 jax | 10 38 | 0 |
| 9 chi | 16 61 | 1 |
| 10 min | 16 162 | 2 |
| 11 den | 8 29 | 0 |
| 12 cin | 16 95 | 1 |
+----------+-------------+----+
| TOTAL | 95 512 | 4 |
+----------+-------------+----+
Total of 244/1055 = 4.32 ypc... 1 TD for every 34.9 carries. Compare that to Barlow's career before today, all of which was accumulated in games with 18 or fewer carries: 391/1778 = 4.55 ypc... 1 TD per 32.6 carries.
I'm not saying Barlow is as good as LT. But no one would term LT as "not bad, not spectacular," despite the fact that he has performed about the same as Barlow with a comparable number of carries. The simple fact is that LT is considered one of the elite RBs in the game due to his other games, the ones with 19+ carries. And we don't know how Barlow will do with 19+ carries, since he's never had that many in a game.
And if you want to see what Barlow does with a larger share of carries, go back to his 18-carry game against AZ - pitiful.
Care to restate this one after today?

He now has two career games with 18 carries, both against Arizona. In those two games he has rushed for 36/205/2 and added 59 yards and 1 TD receiving. That's 44.4 fantasy points in a standard scoring system. Looks to me like the results show he deserves more carries.