i don't know much about historical stuff, but it looks like spritze has the right idea for what you are doing. sounds cools that it can automatically convert the real stats to ratings. didn't know that. only use assign fictional contracts, if necessary... or any of the financial functions on the main league settings page.
If it is still relevant, yes to all of that. but i wouldn't erase service time. that way a 35 year old isn't under club control - if that even applies to your league.
purge will remove deleted entries from the dB and if you delete stats, you might as well delete all retired players, too. it's good to do every ?50 years? depends on the cpu a bit, i guess. just in case of records, i only make use of the "delete those who never make it to the majors" function.
for testing... i make the league as I intend to use it... i sim 30 years, if fictional. i delete history/retired players and such to make it "fresh." i make a backup as is. if i am doing long-term sims, i make necessary settings changes to reduce sim time but keep all tangible functions of the league (ie no pictures, box scores, news etc, i do keep all stats, just in case). i make a backup of this long-term sim setting league for testing.
as long as the both share the exact same origins, i'm confident anything i test will translate. with each backed up, i don't worry about doing somethign stupid. in general, i'd restart any sim from the start date. setting configurations exist that could cause a constant increase or decrease in talent for a long-period of time until a new equillibrium reached. if you don't deviate much from default, i wouldn't worry about that.
and as far as getting better with computers, you just needed some motivation and self-interest in it
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