<attributeGroup name="eventStateBaseball">
    <attribute name="inning-value" type="string" use="optional">
        <annotation>
            <documentation>An integer. 1 through 9 for the main innings. 10, 11, 12, etc. for extra innings.</documentation>
        </annotation>
    </attribute>
    <attribute name="inning-half" use="optional">
        <annotation>
            <documentation>Either top or bottom.</documentation>
        </annotation>
        <simpleType>
            <restriction base="string">
                <enumeration value="top" />
                <enumeration value="bottom" />
            </restriction>
        </simpleType>
    </attribute>
    <attribute name="outs" type="string" use="optional">
        <annotation>
            <documentation>Either 1, 2, or 3.</documentation>
        </annotation>
    </attribute>
    <attribute name="balls" type="string" use="optional">
        <annotation>
            <documentation>Either 1, 2, 3, or 4.</documentation>
        </annotation>
    </attribute>
    <attribute name="strikes" type="string" use="optional">
        <annotation>
            <documentation>Either 1, 2, or 3.</documentation>
        </annotation>
    </attribute>
    <attribute name="runner-on-first" type="string" use="optional">
        <annotation>
            <documentation>Whether or not a player is standing on first base. Either true or false.</documentation>
        </annotation>
    </attribute>
    <attribute name="runner-on-first-idref" type="IDREF" use="optional">
        <annotation>
            <documentation>A pointer to the player on first base.</documentation>
        </annotation>
    </attribute>
    <attribute name="runner-on-second" type="string" use="optional">
        <annotation>
            <documentation>Whether or not a player is standing on second base. Either true or false.</documentation>
        </annotation>
    </attribute>
    <attribute name="runner-on-second-idref" type="IDREF" use="optional">
        <annotation>
            <documentation>A pointer to the player on second base.</documentation>
        </annotation>
    </attribute>
    <attribute name="runner-on-third" type="string" use="optional">
        <annotation>
            <documentation>Whether or not a player is standing on third base. Either true or false.</documentation>
        </annotation>
    </attribute>
    <attribute name="runner-on-third-idref" type="IDREF" use="optional">
        <annotation>
            <documentation>A pointer to the player on third base.</documentation>
        </annotation>
    </attribute>
    <attribute name="runs-this-inning-half" type="string" use="optional">
        <annotation>
            <documentation>An integer.</documentation>
        </annotation>
    </attribute>
    <attribute name="pitcher-idref" type="IDREF" use="optional">
        <annotation>
            <documentation>A pointer to the player element for the pitcher standing on the mound.</documentation>
        </annotation>
    </attribute>
    <attribute name="batter-idref" type="IDREF" use="optional">
        <annotation>
            <documentation>A pointer to the player element for the batter at the plate.</documentation>
        </annotation>
    </attribute>
    <attribute name="batter-side" use="optional">
        <annotation>
            <documentation>Which side of the plate the batter was on when taking the pitch.</documentation>
        </annotation>
        <simpleType>
            <restriction base="string">
                <enumeration value="left" />
                <enumeration value="right" />
            </restriction>
        </simpleType>
    </attribute>
    <attribute name="at-bat-number" type="string" use="optional">
        <annotation>
            <documentation>Incremented throughout game on a per-team basis. A perfect game would have at-bat-number go from 1 to 27 for the team that didn't get any hits.</documentation>
        </annotation>
    </attribute>
    <attribute name="sequence-number" type="string" use="optional">
        <annotation>
            <documentation>Usually an integer</documentation>
        </annotation>
    </attribute>
</attributeGroup>