A sole structure (100; 1400) for an article of footwear, comprising: a reinforcing plate (120; 1200; 1420) defining a first flex groove (131; 1431), a second flex groove (132; 1432), and a third flex groove (133, 1433); wherein the first flex groove (131, 1431) is oriented in a longitudinal direction; wherein the second flex groove (132; 1432) extends from a second flex groove first end at a central portion (122; 1422) of the reinforcing plate (120; 1200; 1420), in an approximately radial direction toward a second flex groove second end at a medial side of the reinforcing plate (120; 1200; 1420); wherein the third flex groove (133; 1433) extends from a third flex groove first end at the central portion (122; 1422) of the reinforcing plate (120; 1200; 1420), in an approximately radial direction toward a third flex groove second end at the medial side of the reinforcing plate (120; 1200; 1420); wherein the third flex groove (133; 1433) is disposed farther from a forward edge of the sole structure (100; 1400) than the second flex groove (132; 1432); wherein the first flex groove (131, 1431) and the second flex groove (132, 1432) form a first flange portion (141, 1221) of the reinforcing plate (120, 1200, 1420); and wherein the first flange portion (141, 1221) corresponds to a big toe of the foot; wherein the second flex groove (132; 1432) and the third flex groove (133; 1433) form a second flange portion (142; 1222; 1422) of the reinforcing plate (120; 1200; 1420); wherein the second flange portion (142; 1222; 1422) has a first end portion connected to the central portion (122; 1422) of the reinforcing plate (120; 1200; 1420) and a second end portion extending to an outer peripheral portion (124; 1424) of the reinforcing plate (120; 1200; 1420); wherein the second flex groove first end is separated from the third flex groove first end at the central portion (122; 1422) to define the first end portion of the second flange portion (142; 1222) and a bending region disposed adjacent to the central portion (122; 1422) of the reinforcing plate (120; 1200; 1420); wherein the second flange portion (142; 1222; 1422) is associated with a cleat member; wherein the second flange portion (142; 1222; 1422) corresponds to a ball region of a foot; and wherein the second flange portion (142; 1222; 1422) bends at the bending region and moves independently from a remaining portion of the reinforcing plate (120; 1200; 1420); characterized in that the second flange portion increases in thickness moving in a direction from the first end portion to the second end portion. a reinforcing plate (120; 1200; 1420) defining a first flex groove (131; 1431), a second flex groove (132; 1432), and a third flex groove (133, 1433); wherein the first flex groove (131, 1431) is oriented in a longitudinal direction; wherein the second flex groove (132; 1432) extends from a second flex groove first end at a central portion (122; 1422) of the reinforcing plate (120; 1200; 1420), in an approximately radial direction toward a second flex groove second end at a medial side of the reinforcing plate (120; 1200; 1420); wherein the third flex groove (133; 1433) extends from a third flex groove first end at the central portion (122; 1422) of the reinforcing plate (120; 1200; 1420), in an approximately radial direction toward a third flex groove second end at the medial side of the reinforcing plate (120; 1200; 1420); wherein the third flex groove (133; 1433) is disposed farther from a forward edge of the sole structure (100; 1400) than the second flex groove (132; 1432); wherein the first flex groove (131, 1431) and the second flex groove (132, 1432) form a first flange portion (141, 1221) of the reinforcing plate (120, 1200, 1420); and wherein the first flange portion (141, 1221) corresponds to a big toe of the foot; wherein the second flex groove (132; 1432) and the third flex groove (133; 1433) form a second flange portion (142; 1222; 1422) of the reinforcing plate (120; 1200; 1420); wherein the second flange portion (142; 1222; 1422) has a first end portion connected to the central portion (122; 1422) of the reinforcing plate (120; 1200; 1420) and a second end portion extending to an outer peripheral portion (124; 1424) of the reinforcing plate (120; 1200; 1420); wherein the second flex groove first end is separated from the third flex groove first end at the central portion (122; 1422) to define the first end portion of the second flange portion (142; 1222) and a bending region disposed adjacent to the central portion (122; 1422) of the reinforcing plate (120; 1200; 1420); wherein the second flange portion (142; 1222; 1422) is associated with a cleat member; wherein the second flange portion (142; 1222; 1422) corresponds to a ball region of a foot; and wherein the second flange portion (142; 1222; 1422) bends at the bending region and moves independently from a remaining portion of the reinforcing plate (120; 1200; 1420); characterized in that the second flange portion increases in thickness moving in a direction from the first end portion to the second end portion.