In baseball RISP opportunities are plate appearances when a batter is up with a runner in scoring position. A runner in scoring position means there is a runner on either second or third that will usually score on any kind of hit.
The following tables show results of a calculation using event data from retrosheet.org. This study counted RISP opportunities for each position of a lineup. Event data are pretty much accurate from around 1972 to 2013 so I split that period into two to see a difference between the two periods. The rates are mostly the same with the 4th and 5th lineup positions seeing the most RISP opportunities and #1 and #2 seeing the least in each period. In general teams want to place high OBP players, players who can get on base and not necessarily hit in RISP situations to bat #1 and #2. Batters who hit well in RISP situations should placed in the part of the lineup where they see the most opportunities. More math is needed to create an optimum solution and it would depend upon the complete set of players a manger has to work with.
The most glaring difference between the two periods is lineup position #2 which seems to have seen a drop off in RISP opportunities in the last 20 years compared to the 20 years before that.
Counting RISP opportunities is only one of many kind of studies that can be done having complete event files. Here is another analysis of RISP done by this data model. Here is an explanation of event data.
|Pos||Total PA||RISP PA||% RISP|
|POS||Total PA||RISP PA||% RISP|