OK just read up on DLS doesn't really answer my question if the storm intensifies and they can't get back out tonight so I'll leave that to you guys. But now I have another question. Bangladesh stands 94/2 after 8 overs. Per DLS and cricinfo the target for Ireland if they get 8 overs is 108. Why do they need 14 more runs than Bangladesh actually accumulated in the same number of overs per DLS. That I do not understand. So technically they could score 100 runs in 8 overs and lose even though they will have more runs than Bangladesh actually got in the same number of overs. I get having rates if they can't bat the same number of overs (its 72 for 5, 84 for 6 and 96 for 7) though on second thought that last makes no sense to me as well. You would think the target would be the target and everything else would flow down from there. Guess I'm never going to be a good at math because by arithmetic this doesn't add up.
The short answer is that they get to use all 10 wickets over those 8 overs, whereas Bangladesh was expecting to need to conserve wickets in order to bat through 20.
The idea is basically this:
When you're batting, you're thinking about how to use your resources as effectively as possible over the time allotted. It's like one of those German board games. As an example from my own batting (middle order batsman, club level in SoCal), if I come in at the very end of an innings, with the goal of just swinging hard at every ball until I get out, I average about 12 runs off 4 balls (18 per over). That's a great run rate, but a typical side only has about 5-6 true batsmen, so you couldn't score 360 runs off 20 overs this way. Rather, our team would typically end up with about 70 runs scored off under 5 overs, but be all out. So, the idea is that there are two kinds of resources, both how many balls you get to face and how many batsmen are remaining. For the latter, technically you have 11 batsmen in a side, but most of the runs will be scored by the top 7-9, with some teams having deeper batting orders than others, depending upon how well their bowlers can bat. If Bangladesh were 94/8 after 8 overs, they would have been likely to score around 105 runs for 20 overs. At 94/2, they were probably looking at a score nearly double that. The D/L total would have been far lower if they were 94/8, reflecting this difference.
So, in practice, early in a 20-over match, my job is partly to score runs at a good rate but also partly to make sure that I don't get out, knowing that we can accelerate our scoring very quickly at the end if we have extra wickets in hand. Essentially, reflecting both kinds of resources. In my case, I usually come in to bat when 2 (later in the innings) or 3 (early in the innings) people are out. So, on the rare occasions that I bat in the first couple of overs, our score might be something like 1/3, and my primary job is to not get out for a while, calm things down, and make sure that we're able to use all of our resources. The last time I was put in that position in a T20, I scored 28 runs off 41 balls (4.1/over), which is really, really slow for a T20 but was what the situation called for -- we got ourselves to 59/5 with 4 overs left and ended up scoring 92/8. We lost anyway, but actually took 7 wickets in reply and gave ourselves a shot, whereas if I had scored a quick 12 off 4 balls, we probably would have ended up with a total under 50.
A more normal situation for me is that I come in around the 10th over and aim to start scoring about 6-8 runs per over and then gradually accelerate until I get out, because as fewer balls remain, it becomes correct to be more aggressive. My actual average over the past couple of seasons is 38 off 25 balls (9/over).
So, the point is that D/L is taking these differences in available resources into account and doing a calculation as to what looks equivalent. It's not fair to compare what Bangladesh did in the *first* 8 overs with what Ireland would do in their *only* 8 overs, because Bangladesh was told to bat through 20.
A smaller effect, but the same idea, would be to imagine that baseball worked the same way. My team bats 9 innings first, and we score 6 runs against your pitching. Now it rains, and you're going to only get to bat for 3 innings. Is scoring 2 runs equivalent? No, of course not -- I get to use my whole pitching staff for those three innings and avoid filling the other 6, so you're only going to face my high-leverage relievers. In baseball, this is a smaller but real effect -- fewer runs are scored in the late innings. [Which brings me to another question to think about -- does that mean you should use a pitching staff differently? But let me keep pondering that one and cut this post off here.]
