I've never used the H/R before as its clearly one of the dumbest mangerial moves ever invented, but I thought I would draft a team with minimal walks, minimal k's, and put them in an optimal environment to see if the H/R could actually provide value under the right circumstances. Pretty unimpressive so far. Team has scored a below average number of runs despite being in a +2 singles park. To be fair, part of the problem is lack of attempts to H/R despite having the setting on '5'. Here is a couple screenshots of the roster...

Do the players have to have a certain speed rating in order for the sim to H/R as often as you want them too?

Preface point: I am an idiot. And I play 90% progs and 10% themes.
The second point in no way proves the first. I have many examples as to why the first is true, but that is a whole 'nuther topic.

But awhile ago in one of these forums, someone posted that if you put your hit/run and base running agress at 5 that the players predisposed (high speed) will be the ones most taking advantage of it, but added that somehow the c's arm plays a role?

So me being me, I believed the poster. So when I have a group on a certain team that has above average speed, I've been putting the settings for h/r & br/ag on 5 and coupled that w/ the advanced hitting individual settings. I noticed more sb's and more runs scored, granted my sample size is small, but even when I moved settings from 3 to 5, it seemed my production went up.

I also noted, if I had a player batting 2nd w/ a low speed rating, the O was not as productive. So I look to put top speed guys at 1 and 2 and no "speed- slouch" hitting 3rd, even if it means giving up some obp. I still look to put my best hitter at 3, but often flip/flop a 3and 5 hitter, if the one hitter has better speed ratings

you had to bring this up huh!
while i have just a few moment to post- let me point you to the posting by flyingman a couple back.... check out that final world series game..4th inning i believe.. " catfish hunter thrown out on the front end of a double steal attempt"  catfish hunter  !!!!!!!
now - when  started here at wis, the owner that brought me on board said " i should allways have my h/r at base running settings at aggressive- to avoid double plays...blah blah blah.. " to which i have held to all along , sometimes incresing them when a poor or poorer catcher are scheduled.
  i have run out of time but i will finish my comment later....btw - i am not crying sour grapes toward flyingman.... he did win in 7 :) and had a great season !

I have always preferred the run and hit play to the hit and run. Still in wis the latter has a use, especially for high sb% guys.

ok so as i said.
during the season this team was 4 /11 in stolen bases ( of which stargell and hunter were both 0/0 )- i have not had a chance to go back and see what games these were in or whether the thrown outs were of the double steal type. - game 1 stargell and milan walk - and stargell is thrown out after a bucky dent k's again. ( milan 0/1 during the season) games 2 through 6 no attempts to run . then game 7  - 3rd inn - hunter get on by fielder choice - mccrae singles to center - then hunter get thrown out on the front end of the double steal.- we score 4 runs in the inning - but might have scored more. flyingmans relief staff shut us down from there. but i just can't see where sparky get this logic? stargell was the 2nd slowest guy (51 speed rating)- next to thurman munson - and hunter is tied with 4 other pitchers with the lowest speed rating (20) on the team. i had them both at 1 in the advanced settings and again, they didnt even attempt during the season, why would i consider changing it if i was getting the desired results. my fastest guy cesar geronimo (84) r/l  13/18 made 416 pa this season with a 2 setting (advanced) - and did not even attempt to steal - he was 0/0.
 this team cleary advance on pitching - ranking below the league avg in rs 824 (1040 was tops/850 avg) and our 4/11 sb was 2nd lowest to the team that scored the 1040 runs- they were 2/3 in sb/cs

In my experiences, when I've seen the hit and run used, it seems most of the time all it does is keep the runner at first out of the DP (which is valuable, for sure.)  But that's what I see 80% of the time...batter out at first, runner gets to second.

I generally set it at 1 though, because I have no clue how it's used by the SIM.  In RL, the runner's speed, contact ability of the hitter and position of the defense would all be big factors in calling it.

I have drafted several teams on the basis of low strikeouts, high contact rate (.900+), high hit rate (.300+) and speed of 70+ (usually including 5 or 6 at 80+). Put them in the Astrodome or AT&T, depending on their Avg+ ratings and the quality of my pitching. All but one of these teams has had a winning record and most made the playoffs. (The loser has had problems with pitching fatigue.) One team is currently ending its regular season in a theme league with the league's best record.

I have not kept track, though, of the number of actual H&R plays and their ratio of success. All I can testify is that the very aggressive settings for H&R and base running can help a team that's built for the running game.