Data quality checks

[jacquietran]

The data obtained from the WNBL / FIBA Livestats site is currently included in this package largely "as is" and needs closer checking as I expect there will be errors.

This issue will start off as a list of checks that could be useful for assessing data quality, and then later on, I will probably create separate issues for each check.

• Check shots missed against rebounds: FGMissed + FTMissed = Individual rebounds + Team rebounds (H/T to NobleQueemoShabazzElBey on Twitch for the suggestion!)
• How is efficiency rating calculated? Could check if the values are the same when using Hollinger's PER.

[jacquietran]

Packages for data quality checking - H/T for the suggestions isomore on Twitch!

• assertr
• validate
• pointblank