A sole structure for an article of footwear, comprising: a lasting board including a flange portion, the flange portion having a first end portion connected to a central portion of the lasting board and a second end portion extending to an outer peripheral portion of the lasting board; wherein the flange portion is formed by a second flex groove and a third flex groove defined by the lasting board; wherein the second flex groove extends from a second flex groove first end at the central portion in an approximately radial direction toward a second flex groove second end at a medial side of the lasting board; wherein the third flex groove extends from a third flex groove first end at the central portion in an approximately radial direction toward a third flex groove second end at the medial side of the lasting board; wherein the third flex groove is disposed farther from a forward edge of the sole structure than the second flex groove; wherein the second flex groove first end is separated from the third flex groove first end at the central portion to define the first end portion of the flange portion and a bending region disposed adjacent to the central portion of the lasting board; wherein the flange portion is narrower at the first end portion and widens toward the second end portion; a cleat member associated with the flange portion; wherein the flange portion corresponds to a ball region of a foot; and wherein the flange portion is capable of bending with the ball region of the foot at the bending region, characterized in that the sole structure further comprises a reinforcing plate including second and third flex grooves (1432, 1433) arranged in a similar configuration to the second and third flex grooves (1532, 1533) of the lasting board. a lasting board including a flange portion, the flange portion having a first end portion connected to a central portion of the lasting board and a second end portion extending to an outer peripheral portion of the lasting board; wherein the flange portion is formed by a second flex groove and a third flex groove defined by the lasting board; wherein the second flex groove extends from a second flex groove first end at the central portion in an approximately radial direction toward a second flex groove second end at a medial side of the lasting board; wherein the third flex groove extends from a third flex groove first end at the central portion in an approximately radial direction toward a third flex groove second end at the medial side of the lasting board; wherein the third flex groove is disposed farther from a forward edge of the sole structure than the second flex groove; wherein the second flex groove first end is separated from the third flex groove first end at the central portion to define the first end portion of the flange portion and a bending region disposed adjacent to the central portion of the lasting board; wherein the flange portion is narrower at the first end portion and widens toward the second end portion; a cleat member associated with the flange portion; wherein the flange portion corresponds to a ball region of a foot; and wherein the flange portion is capable of bending with the ball region of the foot at the bending region, characterized in that the sole structure further comprises a reinforcing plate including second and third flex grooves (1432, 1433) arranged in a similar configuration to the second and third flex grooves (1532, 1533) of the lasting board.