<?php
 
// Dados de entrada:
$linha = 'NICK:KEOME PTS:50 ASTS:6 DEFREB:2 OFFREB:7 STLS:14 BLKS:4 TOS:5 NICK:ARTHUR PTS:10 ASTS:3 DEFREB:5 OFFREB:4 STLS:4 BLKS:2 TOS:6';
 
// Verifica se é possível obter os dados com expressão regular:
if (preg_match_all("/([a-zA-Z]+)\:([a-zA-Z0-9]+)\s?/", $linha, $matches)) {
 
  // Lista de jogadores:
  $players = [];
 
  // Dados do jogador:
  $player = [];
 
  // Percorre todos os valores da entrada:
  foreach(array_map(null, $matches[1], $matches[2]) as $pair) {
 
    // O valor é um nick?
    if (strtoupper($pair[0]) == "NICK") {
 
      // Se houver dados de outro jogador, adicione a lista:
      if ($player) {
        $players[] = $player;
      }
 
      // Inicia os dados do jogador para o nick atual:
      $player = ["name" => $pair[1], "stats" => []];
 
    } else {
 
      // Não é um nick, então só pode ser um status do jogador atual:
      $player["stats"][strtolower($pair[0])] = $pair[1];
    }
  }
 
  // Adiciona à lista os dados do último jogador:
  if ($player) {
    $players[] = $player;
  }
 
  // Exibe a lista de jogadores completa:
  print_r($players);
}

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