Problema na verificação de listas

final List<Card> hand2 = new ArrayList<Card>();
		for (int i = 0; i < 5; i++) {
			hand2.add(gr.pickRandomCard());
		}

		// PLAYER2
		ActionListener two = new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				if (gr1.getCounter2() < 5) {
					gr1.setCounter2(gr1.getCounter2() + 1);
					for (int i = 0; i < arraybtn.length; i++) {
						if (arraybtn[i] == e.getSource()) {
							test3.setIcon(hand2.get(i - 10).getImage());
							pn3.setText(Integer.toString(hand2.get(i - 10)
									.toInt()));
							pn7.setText(hand2.get(i - 10).toString());
							pn70.setText(hand2.get(i - 10).suit());
							gr1.validCard(hand, hand2, i, pn70);
						}
					}
				} else {
					pn7.setText("No more cards");
				}
			}
		};

		for (int i = 10; i < 15; i++) {
			arraybtn[i].addActionListener(two);
			arraybtn[i].setPreferredSize(new Dimension(120, 20));
			arraybtn[i].setText(hand2.get(i - 10).toString());
			contentor3.add(arraybtn[i], gbc);
		}

class FirstGame extends GameRules {
	
	
	@Override
	public boolean validCard(List<Card> hand, List<Card> hand2, int i, JTextField pn70, JTextField pn50) {
		if(pn70.getText().equals (pn50.getText())) {
			return true;
		}
		else {
			for (Card c : hand2) {
				if (c.suit().equals (hand.get(i).suit())) //erro aqui
					return false;
			}
		}
		return true;
	}



	@Override
	public String winer(List<Card> hand, List<Card> hand2, int i,JTextField pn70, JTextField pn50) {
		if (validCard(hand, hand2, i, pn70, pn50) == false) {
			System.out.println("boa");
		}
		else 
			System.out.println("nao tao boa");
		return null;
	}