Up until about a year ago I used to fit the LED in routed grooves in a plastic front panel, to shade each row of LEDs.
It was fiddly and expensive to do, and if the board was pointed towards the North East the sun still got to the LEDs in late afternoon ( we are in the Southern hemisphere )
( I love it when they ask for a southern facing board so it is always shaded )
Now the LEDs are so bright that shading is not needed, but it still needs a double row :-
These are leant back looking straight into the sun so not shaded by the grooves, and are perfectly clear.
The latest ones are even better, and for evening sport the auto dimming I have had to fit turns them right down to less than 10% duty cycle.
One of the problems is that schools and clubs want the scoreboard across the field from the clubhouse, often where there is no power.
Sinking cable around the field is very expensive, and could kill the sale, so if I can get affordable solar panels ( and deep cycle battery ) it might swing some sales.