Stuff

<form id="form1" name="form1" method="post" action="b.php">

<div class="concorrente">
<input type="radio" value="1" name="concorrente1"> 1
<input type="radio" value="2" name="concorrente1"> 2
<input type="radio" value="3" name="concorrente1"> 3
</div>

<div class="concorrente">
<input type="radio" value="1" name="concorrente2"> 1
<input type="radio" value="2" name="concorrente2"> 2
<input type="radio" value="3" name="concorrente2"> 3
</div>


<div class="concorrente">
<input type="radio" value="1" name="concorrente3"> 1
<input type="radio" value="2" name="concorrente3"> 2
<input type="radio" value="3" name="concorrente3"> 3 
</div>


<div class="concorrente">
<input type="radio" value="1" name="concorrente4"> 1
<input type="radio" value="2" name="concorrente4"> 2
<input type="radio" value="3" name="concorrente4"> 3
</div>

<?php $_POST["concorrente1"]; ?>
<?php $_POST["concorrente2"]; ?>
<?php $_POST["concorrente3"]; ?>
<?php $_POST["concorrente4"]; ?>

<label>
<input type="submit" name="enviar" id="enviar" value="Submit" />
</label>
</form>