HI Malcolm,

I grew up in South Africa playing on some good, hard, flat grass pitches many moons ago. Essentially the skills are pretty similar but you will find grass play more upright whilst astro play involves the players getting lower.

For example, grass is probably a little more unpredictable so players are coached to get behind the ball to stop it - like a defensive block. Players also used more upright hitting to move the ball.

Astro is pretty flat and consistent so players particularly at higher levels will bend more at the waist and use a flatter stick to trap ball. They will also use more slap hits passes to move the ball ... they very really use upright hitting.

All this will depend on the level you are coaching and most players adapt pretty quickly but the benefit that astro provides is that players can develop more consistent technical skills and ball pace that isn't always possible on grass.

Good luck.

Cheers
Shelley