master.xml

<data>
  <entry id="1">
    <event>First Game</event>
    <odds>1.2</odds>
    <outcome>Win</outcome>
  </entry>
  <entry id="2">
    <event>Second Game</event>
    <odds>1.8</odds>
    <outcome>Win</outcome>
  </entry>
  <entry id="3">
    <event>Third Game</event>
    <odds>1.75</odds>
    <outcome>Win</outcome>
  </entry>
  <entry id="4">
    <event>Fourth Game</event>
    <odds>2</odds>
    <outcome>Loss</outcome>
  </entry>
  <entry id="5">
    <event>Fifth Game</event>
    <odds>1.15</odds>
    <outcome>Win</outcome>
  </entry>
</data>

master.xsl

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

  <xsl:output method="xml" indent="yes" />
  <xsl:variable name="count" select="count(/data/entry)"/>
  
  <xsl:template match="/data/entry">
	<xsl:param name="total" select="0"/>
	<xsl:param name="price" select="0"/>
	<xsl:variable name="new-total">
		<xsl:choose>
			<xsl:when test="outcome = 'Win'">
				<xsl:value-of select="$total + ($price * odds)"/>
			</xsl:when>
			<xsl:otherwise>
				<xsl:value-of select="$total - ($price)"/>
			</xsl:otherwise>
		</xsl:choose>
	</xsl:variable>
	<xsl:choose>
          	<xsl:when test="not(./following-sibling::entry)">
			<xsl:value-of select="$new-total"/>
		</xsl:when>
		<xsl:otherwise>
                  <xsl:apply-templates select="./following-sibling::entry[1]">
                          <xsl:with-param name="total" select="$new-total"/>
                          <xsl:with-param name="price" select="$price"/>
			</xsl:apply-templates>
		</xsl:otherwise>
	</xsl:choose>
  </xsl:template>

  <xsl:template match="/">
    <xsl:apply-templates select="/data/entry[position() = 1]">
	<xsl:with-param name="price" select="100"/>
    </xsl:apply-templates>
  </xsl:template>

</xsl:stylesheet>