DALLAS (AP) _ Mike Hampton is getting baseball's biggest contract. Now he has to avoid what has been routine for his Colorado Rockies' predecessors: one of its highest ERAs.

The most coveted left-hander on the free-agent market agreed to a $123.8 million, eight-year deal with the Rockies.

``We added a horse,'' Rockies general manager Dan O'Dowd said Saturday. ``His leadership in the clubhouse will be very important for us in the next eight years.''

Hampton, 28, went 15-10 for the New York Mets last season and was MVP of the NL championship series. He is the second prominent left-hander to sign with Colorado this week, following Denny Neagle, who agreed Monday to a $51.5 million, five-year deal.

Hampton has a 6.88 career ERA at Coors Field.

In total dollars, the deal surpasses the previous high of $116.5 million, a nine-year contract Ken Griffey Jr. agreed to with the Cincinnati last February. The previous high for a pitcher had been Kevin Brown's $105 million, seven-year contract with Los Angeles.

The highest total contract in sports is Kevin Garnett's $126 million, six-year deal with the NBA's Minnesota Timberwolves, which averages $21 million. The highest average salary agreed to is $29.5 million, which will be earned by Shaquille O'Neal of the Los Angeles Lakers in an $88.5 million, three-year extension that starts with the 2003-04 season.

Hampton's contract, which includes a club option for 2009, is the longest for a pitcher since Wayne Garland signed a 10-year deal with Cleveland in 1977.

Hampton's average salary of $15,475,000 becomes the highest for a pitcher and is the second-highest in baseball behind Toronto first baseman Carlos Delgado, who will average $17 million in his four-year contract.

Hampton's deal calls for a $20 million signing bonus, $1 million payable to charity and $19 million deferred without interest until after the contract expires. The remaining money will be paid in 10 yearly installments of $1.9 million, the money accruing 3 percent interest.

Because of the deferred money, baseball officials calculate its annual average value at just under $14 million in present-day dollars.

St. Louis had been the other finalist to sign Hampton, and Atlanta, Texas and the Chicago Cubs were interested.

New York general manager Steve Phillips said all interested teams offered $100 million or more.

``It didn't come down to the last dollar,'' Phillips said. ``All the clubs were close enough. It came down to other issues, like the chance to win and quality of life for his family.''