Why does 1,3-pentadiene follow Markovnikov's rule in HBr addition?

Why does 1,3-pentadiene follow Markovnikov's rule in HBr addition?
The addition of HBr to 1,3-pentadiene is governed by carbocation stability. In 1,2-addition, placing hydrogen at C1 yields a secondary carbocation, while placing it at C2 yields a primary carbocation; the former is more stable, favoring Markovnikov addition. Anti-Markovnikov products require peroxide (ROOR) via a radical pathway. For 1,4-addition, the conjugated system allows delocalization, and product distribution depends on whether the hydrogen attaches to C1 or C4. This mechanistic nuance matters industrially because 1,3-pentadiene is a C5 stream byproduct, and controlling regioselectivity in functionalization affects the quality of downstream products like petroleum resins and specialty elastomers. Understanding these pathways helps producers optimize reaction conditions for higher-value derivatives.