A process for producing a conjugated diene monovinylarene block copolymer with a target hardness, the process comprising: (a) contacting a monovinylarene monomer, a conjugated diene monomer, and an initiator in a predetermined sequence under polymerization conditions in a polymerization reactor system, and thereafter coupling and/or terminating to form the copolymer; wherein the predetermined sequence comprises a dual charge of the monovinylarene monomer and the conjugated diene monomer and is sequence i-S-i-S-(S/B)-(S/B)-(S/B)-X, wherein S is a monovinylarene charge, (S/B) is a dual charge of the monovinylarene and conjugated diene to produce a mixed block, each i is an initiator, and X represents a coupling agent or a terminating agent; and (b) controlling an amount of a modifier introduced into the polymerization reactor system to produce the copolymer with the target hardness, which process further comprises measuring the hardness, and adjusting an amount of the modifier introduced into the polymerization reactor system based on a difference between the measured hardness and a target hardness; wherein • the monovinylarene monomer is styrene; the conjugated diene monomer is a butadiene; and the target hardness is a target Shore A hardness in a range from 60 to 90; • the copolymer is a styrene butadiene block copolymer; • the copolymer has a Mn in a range from 10,000 to 500,000 g/mol and a MFR in a range from 1 to 30 g/10 min; • the block copolymer comprises from 55 phm to 70 phm monovinylarene monomer, and comprises polymer chains containing a block structure having formula: S 1 - (S/B) 1; wherein: S 1 is a monoblock of the monovinylarene monomer, wherein S 1 is from 10 phm to 45 phm of the copolymer; and (S/B) 1 is three mixed blocks of the conjugated diene monomer and the monovinylarene monomer, wherein the monovinylarene monomer content is from 20 wt. % to 80 wt. %, based on the total weight of (S/B) 1. (a) contacting a monovinylarene monomer, a conjugated diene monomer, and an initiator in a predetermined sequence under polymerization conditions in a polymerization reactor system, and thereafter coupling and/or terminating to form the copolymer; wherein the predetermined sequence comprises a dual charge of the monovinylarene monomer and the conjugated diene monomer and is sequence i-S-i-S-(S/B)-(S/B)-(S/B)-X, wherein S is a monovinylarene charge, (S/B) is a dual charge of the monovinylarene and conjugated diene to produce a mixed block, each i is an initiator, and X represents a coupling agent or a terminating agent; and (b) controlling an amount of a modifier introduced into the polymerization reactor system to produce the copolymer with the target hardness, which process further comprises measuring the hardness, and adjusting an amount of the modifier introduced into the polymerization reactor system based on a difference between the measured hardness and a target hardness; wherein • the monovinylarene monomer is styrene; the conjugated diene monomer is a butadiene; and the target hardness is a target Shore A hardness in a range from 60 to 90; • the copolymer is a styrene butadiene block copolymer; • the copolymer has a Mn in a range from 10,000 to 500,000 g/mol and a MFR in a range from 1 to 30 g/10 min; • the block copolymer comprises from 55 phm to 70 phm monovinylarene monomer, and comprises polymer chains containing a block structure having formula: S 1 - (S/B) 1; wherein: S 1 is a monoblock of the monovinylarene monomer, wherein S 1 is from 10 phm to 45 phm of the copolymer; and (S/B) 1 is three mixed blocks of the conjugated diene monomer and the monovinylarene monomer, wherein the monovinylarene monomer content is from 20 wt. % to 80 wt. %, based on the total weight of (S/B) 1. • the monovinylarene monomer is styrene; the conjugated diene monomer is a butadiene; and the target hardness is a target Shore A hardness in a range from 60 to 90; the conjugated diene monomer is a butadiene; and the target hardness is a target Shore A hardness in a range from 60 to 90; • the copolymer is a styrene butadiene block copolymer; • the copolymer has a Mn in a range from 10,000 to 500,000 g/mol and a MFR in a range from 1 to 30 g/10 min; • the block copolymer comprises from 55 phm to 70 phm monovinylarene monomer, and comprises polymer chains containing a block structure having formula: S 1 - (S/B) 1; wherein: S 1 is a monoblock of the monovinylarene monomer, wherein S 1 is from 10 phm to 45 phm of the copolymer; and (S/B) 1 is three mixed blocks of the conjugated diene monomer and the monovinylarene monomer, wherein the monovinylarene monomer content is from 20 wt. % to 80 wt. %, based on the total weight of (S/B) 1. S 1 is a monoblock of the monovinylarene monomer, wherein S 1 is from 10 phm to 45 phm of the copolymer; and (S/B) 1 is three mixed blocks of the conjugated diene monomer and the monovinylarene monomer, wherein the monovinylarene monomer content is from 20 wt. % to 80 wt. %, based on the total weight of (S/B) 1.