André Santos led Goa's remarkable turnaround.56 games. 121 goals. 379 saves. And non-stop action throughout. The inaugural Hero Indian Super League (ISL) season has enthralled crowds across the eight venues and audiences nationwide. As the league heads into the semifinals, indiansuperleague.com takes a look back at the second half of the league phase.FC Goa’s stunning form was the story during the second half of the league phase. Languishing at the bottom of the table at the midway point, Brazil legend Zico’s charges went all seven games unbeaten. The turnaround was evident at both ends of the pitch. After five goals in their first seven games, the Goa attack exploded to score 16 goals in the next seven, with Czech striker Miroslav Slepička (5 goals, 4 assists) and Brazilian André Santos (4 goals – 3 in the second half of the season – and 3 assists) leading the way. And a defence which had kept only one clean sheet during the first seven games morphed into a solid unit, letting in only three goals and keeping four clean sheets, and keeper Jan Šeda is now leading the race for the Golden Glove award. Goa narrowly missed out on top spot, drawing their final game against Kolkata – a win would have moved them up to first.Marco Materazzi’s Chennaiyin FC ended the first half of the league phase in second place, level on points with Atlético de Kolkata but behind on goal difference. A 3-1 win over FC Pune City took them to top spot, which they did not relinquish for the rest of the season. They lost league top-scorer Elano and the team’s second-leading scorer Stiven Mendoza to injury, but Bruno Pelissari stepped into the void and scored some spectacular goals to ensure the Chennaiyin juggernaut rolled on.Bruno Pelissari's goals made sure Chennaiyin didn't miss Elano and Mendoza.Kolkata’s indifferent form was a surprise. After leading the league at the midway point, they won only once in the second half of the season. The goals dried up for Antonio López Habas’ side. Having scored 11 in their first seven games, Kolkata scored only five in their next seven. They nearly slipped out of the semifinal spots entirely. With less than half an hour left in their final game, Kolkata were heading out of the tournament. Star striker Fikru’s penalty levelled the scores against Goa and earned them the point they needed to qualify for the semifinals.Kerala Blasters FC rode their defensive solidity into the top four. David James’ side conceded just five goals in seven matches in the latter half of the league, finishing with the best goals against record (11) among the eight teams. Their strikeforce continued to struggle, hitting the back of the net only four times in the seven games, but Kerala did just enough to make it into the semis. A 1-0 win against Pune City in their last match booked their semifinal spot.Delhi Dynamos FC, Pune City, NorthEast United FC, and Mumbai City FC were left on the outside looking in. Delhi came closest, with Brazilian wizard Gustavo dos Santos setting the league alight, scoring some brilliant goals. Harm van Veldhoven’s men went unbeaten over their last five matches, including a spirited fightback from 2-0 down against Chennaiyin to get a draw in their final game, but it was not enough, with Kolkata’s draw against Goa knocking Delhi out. Meanwhile, Franco Colomba’s Pune City, third at the halfway point, suffered a downturn in form, losing four of their last seven games. A win over Mumbai City gave them hope, but losses to Delhi and Kerala ultimately spelled doom for the Pune club.Gustavo dos Santos' magical form was not enough for Delhi Dynamos.Peter Reid’s Mumbai City had ended the first half of the season in fourth. But the defensive solidity that had underpinned their surge into the top four disappeared during three straight losses – 3-0 to Chennaiyin, 4-1 to Delhi, and 2-0 to Pune City – and the strikeforce never got it going, scoring four goals over the last seven games. NorthEast were marginally better, scoring five – three in a stunning win over Chennaiyin that revived their semifinal hopes, but that was their only win during the second half of the campaign. However, head coach Ricki Herbert has built a strong team with a young Indian core which will have gained immensely from their ISL experience.All four teams can count themselves unfortunate, as a few results here and there would have changed things drastically, showcasing the exciting unpredictability of the ISL.