Outdoors the surface is a lot slower due to increased Friction. This increase in Friction means the bowl slows down much quicker and also means the effect of Bias is vastly reduced. So with the SAME set of Bowls, to bowl on an Indoor carpet you need to bowl WIDE and SLOW whereas Outdoors you need to bowl NARROW and FAST in order to end up at the same set Jack distance.
Also, Outdoors the rink/grass is not uniform, it may well have ridges and dips in it (impossible to see by eye). This means outdoors your Aiming Point (the angle of it) may very well be different on different hands.
Overall Outdoors in a much narrower line (as explained by increased Friction and less bias effect) BUT even within that narrowing, you may well have ‘one hand’ being narrower than the other.
See how the AP changes Indoor to Outdoor but also the uniformity Indoors and a significant difference Outdoors BH to FH (as an example where one hand is much narrower than the other…. this never happens Indoors, because the surface is uniform).
Adjusting your AP is simple enough to do. If you can bowl reliably to a given AP, you’ll have no difficulty in bowling to a different AP. The skill is choosing which AP you need to bring your wood to the centreline.
Outdoors is generally more forgiving. A small error in your line or your weight ISN’T heavily punished unlike it is when bowling Indoors. But Outdoors is about constant minor changes. The green will slow if it starts to rain. It slows because wet grass has more friction than dry grass. So, this means the bias effect will be even less than before SO your AP will narrow compared to the AP you were using when it wasn’t raining. Increased Friction will also slow your wood down SO what speed you were using to get to a set jack length will need to INCREASE to get to the same length. All of this works in reverse if you started when it was damp and the sun comes out and the grass surface starts to dry …. New AP, New Weight … Outdoors is all about making constant adjustments … so when to make them and how.
That’s basic drawing shots, but the same applies to weighted shots. The WEIGHT and the LINE is different Indoors and Outdoors …. Precisely because the different Friction/Speed of the two surfaces.
By way of example consider just two common weighted shots. Trailing the Jack and Promoting a Wood.
Because the surfaces are ‘vastly’ different, the line you need to ‘hit’ the target and the ‘speed’ you need to ‘hit’ it with, are vastly different to get the same result … say you want to trail the Jack by 3 feet or promote a wood by 1 foot … you’ll need two completely different lines and two completely different weights/speeds depending if you’re indoors or outdoors. Simplistically, Indoors you’ll need a wide biased line and a slow impact … Outdoors, you’ll need a narrow biased line and a fast impact. Because of the friction difference, the two overall results will be the same. See (Fig.2)
Also when trailing the Jack Indoors and Outdoors there’s normally a difference in the final separation distance between the wood and the Jack. This is also most probably due to the surface Friction differencesIndoors at the point of contact there’s sufficient energy to ‘start’ the Jack rolling ‘ahead’ of the wood and so there’s normally a significant gap between them when they both come to rest.
Outdoors at the point of contact there’s the same energy transfer but friction appears to delay the movement of the Jack and so they Jack and wood ‘move’ together and come to rest adjacent to each other.
So even when you hit the Jack ‘full’, Indoors the Jack moves ‘away’ from the wood whereas Outdoors they nearly always ‘stick’ together.
Considering promoting a wood
Because of the Friction differences, it’s a given that you’ll need to hit the target a lot harder Outdoors than Indoors to move it the same distance. As previously discussed, the line will also be narrower Outdoors than Indoors to actually ‘hit’ it.
You also probably know that there’s a weight (speed of contact) difference between promoting a wood that’s on its running surface and a wood that’s sitting ‘flat’ (to move them the same distance).
If the wood is lying flat, it takes a ‘bigger’ contact force to move it. This fact is the same for Indoors and Outdoors (although the force is reduced for both promotions indoors compared to the force to do both outdoors)
As already discussed, the reason for the speed differences is due to the Friction differences of the surfaces. BUT these Friction differences also result in differences in the resting bowl positions of all deliveries to start with. So, considering the bowl you’re trying to promote/hit, when Outdoors it will normally be sitting on its running surface. This is because Outdoors the friction is higher, this means the wood bends less (so the bias effect is less) AND it also slows down quicker ….. this means that most woods outdoors stop on their running surfaces. Meaning they are ‘easier’ to promote.
Indoors the wood takes much longer to slow, the bias effect is much higher and so the wood bends more. This means the wood takes ages to slow and bends a lot more and SO nearly always topples and sits ‘flat’ when it comes to rest. This means indoors you’re normally trying to promote a wood sitting flat and so you need to ‘hit’ it harder than one on its running surface.