I saw a 14 or 15 year old kid increase her pitch speed by about 10 miles an hour in about a 3 hour time span. This is how she did it.
She was throwing between 55 and 58. Someone saw it on a radar And told someone "she's throwing in the mid to upper 50s."
That person told someone "she's throwing in the high 50s."
That person told someone "she's throwing 59."
That person said "she's throwing the low 60s."
That person told someone "she's throwing 64."
That person told someone "she's tharowing in the mid 60s."
That person told someone "she's throwing any where between 65 and 68..."
If every one didn't have some where else to be I'm sure she could have cracked 100..