When did the true "series" concept begin

[G1911]

Originally Posted by rats60

1955 Topps and Bowman are skip numbered because the first series of each are not 1-x as the OP required making 1956 the first year when this practice "took hold."

So by skip numbered, you mean series 1 and only series 1 has to every card in sequential order without skipped numbers, so it's okay for 1958 and 1961 but not other set? Or 1958 and 1961 are not skip numbered because those numbers were never issued? Thus there can be missing numbers, but the cards actually released must be in order without a skipped number but ? And 1952 Topps does not count because 1953 had skipped numbers and we are ignoring the thread title question to use your definition of "took hold", and 1934 Goudey and C46 doesn't count because there weren't enough numbered sets after it to 'take hold' as to take hold requires X quantity of immediate successors from the same firm or something, but those successors can skip numbers entirely if they follow 1956 Topps, and Play Ball's don't count because they just don't or something.

I'm going to say it's 1982 Topps because I've made up some extra parameters to make nothing else qualify for consideration, and give up on discerning all the unstated additional rules it takes to arrive at the desired result and only that result.